# Thread: Planewalking – a guide for bending time and space

1. ## Planewalking – a guide for bending time and space

It's bigger on the inside!

I have always been a Planescape aficionado - planar hopping adventures have a mystique of their own, but sadly, there are very few character concepts that actually play around with planewalking and space-time bending. 3.5 has very little material regarding planar mechanics, and, therefore, very little material explicitly targeted at those concepts.
Presented below is a collection of musings regarding planar manipulation - ways to creatively employ extra or nondimensional spaces, planar traits, portal destination, and teleportation effects to invoke the feeling of playing a proper planewalker.
This Handbook (hopefully) addresses this sort of hero: warping boundaries between planes, banishing enemies to extradimensional spaces, hiding in the nooks and crevices between realities to escape your foes, bending planar traits to your will. So, how to do all that and still get home before dinner?

On the basics of the space-time continuum

First and foremost, we need to get to the basics: planar traits. For your convenience, here is what the SRD (or the DMG, for that matter) has to say about this - http://www.d20srd.org/srd/planes.htm.

Planar Traits

Each plane of existence has its own properties—the natural laws of its universe.
Planar traits are broken down into a number of general areas.
All planes have the following kinds of traits.

Physical Traits
These traits determine the laws of physics and nature on the plane, including how gravity and time function.

Spoiler

Gravity
The direction of gravity’s pull may be unusual, and it might even change directions within the plane itself.

Normal Gravity
Most planes have gravity similar to that of the Material Plane. The usual rules for ability scores, carrying capacity, and encumbrance apply. Unless otherwise noted in a description, it is assumed every plane has the normal gravity trait.

Heavy Gravity
The gravity on a plane with this trait is much more intense than on the Material Plane. As a result, Balance, Climb, Jump, Ride, Swim, and Tumble checks incur a -2 circumstance penalty, as do all attack rolls. All item weights are effectively doubled, which might affect a character’s speed. Weapon ranges are halved. A character’s Strength and Dexterity scores are not affected. Characters who fall on a heavy gravity plane take 1d10 points of damage for each 10 feet fallen, to a maximum of 20d10 points of damage.

Light Gravity
The gravity on a plane with this trait is less intense than on the Material Plane. As a result, creatures find that they can lift more, but their movements tend to be ungainly. Characters on a plane with the light gravity trait take a -2 circumstance penalty on attack rolls and Balance, Ride, Swim, and Tumble checks. All items weigh half as much. Weapon ranges double, and characters gain a +2 circumstance bonus on Climb and Jump checks.

Strength and Dexterity don’t change as a result of light gravity, but what you can do with such scores does change. These advantages apply to travelers from other planes as well as natives.

Falling characters on a light gravity plane take 1d4 points of damage for each 10 feet of the fall (maximum 20d4).

No Gravity
Individuals on a plane with this trait merely float in space, unless other resources are available to provide a direction for gravity’s pull.

Objective Directional Gravity
The strength of gravity on a plane with this trait is the same as on the Material Plane, but the direction is not the traditional “down” toward the ground. It may be down toward any solid object, at an angle to the surface of the plane itself, or even upward.

In addition, objective directional gravity may change from place to place. The direction of “down” may vary.

Subjective Directional Gravity
The strength of gravity on a plane with this trait is the same as on the Material Plane, but each individual chooses the direction of gravity’s pull. Such a plane has no gravity for unattended objects and nonsentient creatures. This sort of environment can be very disorienting to the newcomer, but is common on “weightless” planes.

Characters on a plane with subjective directional gravity can move normally along a solid surface by imagining “down” near their feet. If suspended in midair, a character “flies” by merely choosing a “down” direction and “falling” that way. Under such a procedure, an individual “falls” 150 feet in the first round and 300 feet in each succeeding round. Movement is straight-line only. In order to stop, one has to slow one’s movement by changing the designated “down” direction (again, moving 150 feet in the new direction in the first round and 300 feet per round thereafter).

It takes a DC 16 Wisdom check to set a new direction of gravity as a free action; this check can be made once per round. Any character who fails this Wisdom check in successive rounds receives a +6 bonus on subsequent checks until he or she succeeds.

Time
The rate of time’s passage can vary on different planes, though it remains constant within any particular plane. Time is always subjective for the viewer. The same subjectivity applies to various planes. Travelers may discover that they’ll pick up or lose time while moving among the planes, but from their point of view, time always passes naturally.

Normal Time
This trait describes the way time passes on the Material Plane. One hour on a plane with normal time equals one hour on the Material Plane. Unless otherwise noted in a description, every plane has the normal time trait.

Timeless
On planes with this trait, time still passes, but the effects of time are diminished. How the timeless trait can affect certain activities or conditions such as hunger, thirst, aging, the effects of poison, and healing varies from plane to plane.

The danger of a timeless plane is that once one leaves such a plane for one where time flows normally, conditions such as hunger and aging do occur retroactively.

Flowing Time
On some planes, time can flow faster or slower. One may travel to another plane, spend a year there, then return to the Material Plane to find that only six seconds have elapsed. Everything on the plane returned to is only a few seconds older. But for that traveler and the items, spells, and effects working on him, that year away was entirely real.

When designating how time works on planes with flowing time, put the Material Plane’s flow of time first, followed by the same flow in the other plane.

Erratic Time
Some planes have time that slows down and speeds up, so an individual may lose or gain time as he moves between the two planes. The following is provided as an example.

d% Time on Material Plane Time on Erratic Time Plane
01-10 1 day 1 round
11-40 1 day 1 hour
41-60 1 day 1 day
61-90 1 hour 1 day
91-100 1 round 1 day
To the denizens of such a plane, time flows naturally and the shift is unnoticed.

If a plane is timeless with respect to magic, any spell cast with a noninstantaneous duration is permanent until dispelled.

Morphic Traits
This trait measures how easily the basic nature of a plane can be changed. Some planes are responsive to sentient thought, while others can be manipulated only by extremely powerful creatures. And some planes respond to physical or magical efforts.

Alterable Morphic
On a plane with this trait, objects remain where they are (and what they are) unless affected by physical force or magic. You can change the immediate environment as a result of tangible effort.

Highly Morphic
On a plane with this trait, features of the plane change so frequently that it’s difficult to keep a particular area stable. Such planes may react dramatically to specific spells, sentient thought, or the force of will. Others change for no reason.

Magically Morphic
Specific spells can alter the basic material of a plane with this trait.

Divinely Morphic
Specific unique beings (deities or similar great powers) have the ability to alter objects, creatures, and the landscape on planes with this trait. Ordinary characters find these planes similar to alterable planes in that they may be affected by spells and physical effort. But the deities may cause these areas to change instantly and dramatically, creating great kingdoms for themselves.

Static
These planes are unchanging. Visitors cannot affect living residents of the plane, nor objects that the denizens possess. Any spells that would affect those on the plane have no effect unless the plane’s static trait is somehow removed or suppressed. Spells cast before entering a plane with the static trait remain in effect, however.

Even moving an unattended object within a static plane requires a DC 16 Strength check. Particularly heavy objects may be impossible to move.

Sentient
These planes are ones that respond to a single thought— that of the plane itself. Travelers would find the plane’s landscape changing as a result of what the plane thought of the travelers, either becoming more or less hospitable depending on its reaction.

Elemental and Energy Traits
Four basic elements and two types of energy together make up everything. The elements are earth, air, fire, and water. The types of energy are positive and negative. These traits determine the dominance of particular elemental or energy forces.

Spoiler
Elemental And Energy Traits

The Material Plane reflects a balancing of those elements and energies; all are found there. Each of the Inner Planes is dominated by one element or type of energy. Other planes may show off various aspects of these elemental traits. Many planes have no elemental or energy traits; these traits are noted in a plane’s description only when they are present.

Air-Dominant
Mostly open space, planes with this trait have just a few bits of floating stone or other elements. They usually have a breathable atmosphere, though such a plane may include clouds of acidic or toxic gas. Creatures of the earth subtype are uncomfortable on air-dominant planes because they have little or no natural earth to connect with. They take no actual damage, however.

Earth-Dominant
Planes with this trait are mostly solid. Travelers who arrive run the risk of suffocation if they don’t reach a cavern or other pocket within the earth. Worse yet, individuals without the ability to burrow are entombed in the earth and must dig their way out (5 feet per turn). Creatures of the air subtype are uncomfortable on earth dominant planes because these planes are tight and claustrophobic to them. But they suffer no inconvenience beyond having difficulty moving.

Fire-Dominant
Planes with this trait are composed of flames that continually burn without consuming their fuel source. Fire-dominant planes are extremely hostile to Material Plane creatures, and those without resistance or immunity to fire are soon immolated.

Unprotected wood, paper, cloth, and other flammable materials catch fire almost immediately, and those wearing unprotected flammable clothing catch on fire. In addition, individuals take 3d10 points of fire damage every round they are on a fire-dominant plane. Creatures of the water subtype are extremely uncomfortable on fire-dominant planes. Those that are made of water take double damage each round.

Water-Dominant
Planes with this trait are mostly liquid. Visitors who can’t breathe water or reach a pocket of air will likely drown. Creatures of the fire subtype are extremely uncomfortable on water-dominant planes. Those made of fire take 1d10 points of damage each round.

Positive-Dominant
An abundance of life characterizes planes with this trait. The two kinds of positive-dominant traits are minor positive-dominant and major positive-dominant. A minor positive-dominant plane is a riotous explosion of life in all its forms. Colors are brighter, fires are hotter, noises are louder, and sensations are more intense as a result of the positive energy swirling through the plane. All individuals in a positive-dominant plane gain fast healing 2 as an extraordinary ability.

Major positive-dominant planes go even further. A creature on a major positive-dominant plane must make a DC 15 Fortitude save to avoid being blinded for 10 rounds by the brilliance of the surroundings. Simply being on the plane grants fast healing 5 as an extraordinary ability. In addition, those at full hit points gain 5 additional temporary hit points per round. These temporary hit points fade 1d20 rounds after the creature leaves the major positive-dominant plane. However, a creature must make a DC 20 Fortitude save each round that its temporary hit points exceed its normal hit point total. Failing the saving throw results in the creature exploding in a riot of energy, killing it.

Negative-Dominant
Planes with this trait are vast, empty reaches that suck the life out of travelers who cross them. They tend to be lonely, haunted planes, drained of color and filled with winds bearing the soft moans of those who died within them. As with positive-dominant planes, negative-dominant planes can be either minor or major. On minor negative-dominant planes, living creatures take 1d6 points of damage per round. At 0 hit points or lower, they crumble into ash.

Major negative-dominant planes are even more severe. Each round, those within must make a DC 25 Fortitude save or gain a negative level. A creature whose negative levels equal its current levels or Hit Dice is slain, becoming a wraith. The death ward spell protects a traveler from the damage and energy drain of a negative-dominant plane.

Magic Traits
Magic works differently from plane to plane, and magic traits set the boundaries for what it can and can’t do.

Spoiler
A plane’s magic trait describes how magic works on the plane compared to how it works on the Material Plane. Particular locations on a plane (such as those under the direct control of deities) may be pockets where a different magic trait applies.

Normal Magic
This magic trait means that all spells and supernatural abilities function as written. Unless otherwise noted in a description, every plane has the normal magic trait.

Wild Magic
On a plane with the wild magic trait spells and spell-like abilities function in radically different and sometimes dangerous ways. Any spell or spell-like ability used on a wild magic plane has a chance to go awry. The caster must make a level check (DC 15 + the level of the spell or effect) for the magic to function normally. For spell-like abilities, use the level or HD of the creature employing the ability for the caster level check and the level of the spell-like ability to set the DC for the caster level check. Failure on this check means that something strange happens; roll d% and consult the following table.

Impeded Magic
Particular spells and spell-like abilities are more difficult to cast on planes with this trait, often because the nature of the plane interferes with the spell.

To cast an impeded spell, the caster must make a Spellcraft check (DC 20 + the level of the spell). If the check fails, the spell does not function but is still lost as a prepared spell or spell slot. If the check succeeds, the spell functions normally.

Enhanced Magic
Particular spells and spell-like abilities are easier to use or more powerful in effect on planes with this trait than they are on the Material Plane.

Natives of a plane with the enhanced magic trait are aware of which spells and spell-like abilities are enhanced, but planar travelers may have to discover this on their own.

If a spell is enhanced, certain metamagic feats can be applied to it without changing the spell slot required or the casting time. Spellcasters on the plane are considered to have that feat or feats for the purpose of applying them to that spell. Spellcasters native to the plane must gain the feat or feats normally if they want to use them on other planes as well.

Limited Magic
Planes with this trait permit only the use of spells and spell-like abilities that meet particular qualifications.

Magic can be limited to effects from certain schools or subschools, to effects with certain descriptors, or to effects of a certain level (or any combination of these qualities). Spells and spell-like abilities that don’t meet the qualifications simply don’t work.

These planes have no magic at all. A plane with the dead magic trait functions in all respects like an antimagic field spell. Divination spells cannot detect subjects within a dead magic plane, nor can a spellcaster use teleport or another spell to move in or out. The only exception to the “no magic” rule is permanent planar portals, which still function normally.

Planar Geometry
As pointed out by martixy, Planar Geometry is a metaplanar concept that allows you to properly bend space by the usage of Coexistent planes.

Spoiler
Originally Posted by martixy
Higher dimensional geometry is an arcane topic even by nerd standards, and not in the D&D sense (any mathematicians/topologists in da house?). Having even a rudimentary intuition for working with higher dimensions is, I suspect, not something the lay-reader is likely to possess. So, if you don't want your brain to melt, you are completely justified in skipping the next couple paragraphs. If you are brave, or foolish enough however, read on!
It is also not something that is given good treatment by the rules, although to my significant surprise when I was first getting into the wider D&D cosmology, it is given some treatment, even if it's so damn basic it creates more confusion than clarity. The impenetrability of the topic is likely why it wasn't developed further.

But establishing a proper geometry can be key in how one navigates a setting's planar landscape. What you can do and can't do, where you can do it, etc.

We'll start with the basics laid out in the Manual of the Planes.
Planes can be coterminous and coexistent:
Coterminous: The planes touch each other. At the points where they touch travel is possible. Think of a pair of spheres touching. Coterminous means being coexistent only in certain points.
Coexistent: The planes overlap each other. Coexistent means being coterminous in a non-null set of neighbouring points. There exist 3 possible types of relationships in this case.

Injective coexistent(every-1-to-not-every-other-1): Where travel is possible from the smaller plane to the larger plane anywhere on the smaller plane, but not the other way around. This means there are places on the larger plane that do not have a corresponding point on the smaller plane.
Surjective coexistent(many-to-1): Multiple points on the larger plane correspond to a single point on the smaller plane. Travel is always possible between these planes, however not all points of the larger plane can be gotten to from the smaller.
Bijective coexistent(every-1-to-every-other-1): The planes are essentially the exact same size and all points on one have a direct correspondence to the other.
These relationships can also be mixed within a single plane (or pair of planes) - one local region might be bijective, a different local region might be surjective. Are these relationships static? If point A links to point B today, does it still link to point B tomorrow?

You might also consider if a single point of contact is enough to create a traversable link between two planes. In a case where the answer is "no" there's some further considerations(not to mention further blurring the line between coterminous and coexistent):

- What is the minimum overlap needed to create a traversable link? Does the minimum depend on external factors? Creature size going through? Intrinsic planar properties? Neighbouring effects?
- Can both types of mechanics coexist? Is a point contact enough for nagivating between one set of planes, but not enough between another?
- What are the consequenses for trying to use an unstable link? And failing?

This is cool for the mathsier nerds because (apart from being interesting) it can help us make create a more unique and consistent setting and a lot of interesting and novel challenges and puzzles for players.
For example, you could create a 4 dimensional maze, by having a normal 3d maze that spans multiple planes.
For reference: https://puzzling.stackexchange.com/q...-maze-creation
For example, you could create a maze that spans the material, ethereal and astral plane, like so:
Spoiler: 3x3x3x3 maze

There is of course, the matter of securing the maze against bypass by perspicacious adventurers with access to teleport or similar effects. This is where my mechanical contribution to this thread comes in:
Stuff of substance(get it?): There's a very obscure special material called Solid positive energy found in the high-level adventure Bastion of Broken Souls. Any space enclosed by this material is impenetrable to any sort of teleportation or divination magic, but the effect does not extend past the material itself. Therefore it works like a cage for planar travel.
Other ideas I've had are weird puzzle-like heists, except in higher dimensions, limiting planar travel to planar gateways, which has setting-level implications, logically consistent ways to kill tippyverse mechanics, multi-dimensional palaces, multi-dimensional creatures, creative twists on the classic portable hole/bag of holding warhead, curses involving planar geometry (e.g. cursing you to exist in multiple planes - your head might be on the material, your legs on the shadow plane, your torso on the plane of fire), general sci-fi stuff like wormholes, warp space, etc.

As is, the most directly useful traits for players are Gravity, Time, Magic, Elemental and Energy, and finally Morphic traits.

Gravity traits could mean flying freely or even nuking enemies with impossibly heavy falling rocks. Not to mention creating a hard time for people to move around in zero G environments. If you’re a long-time D&D player, you are familiar with the all-time fun Reverse Gravity spell, so I shouldn't be the one cracking it to the crowd out there, how an immense area of a naturally occurring 7th level spell is deviously prone to abuse.

Time and Magic traits are victims of constant abuse: from the early 3.0 days, through the 3.5 update, up until this Monday, last I checked. If you really want me to beat on a dead horse, messing with Time traits can range from unlimited duration spells to taking an arbitrary amount of actions per turn, whilst tinkering with Magic traits means you will be loading on free metamagics until your ears bleed; or that your opponents will have a real hard time casting spells.

Elemental and Energy traits are reasonably modest when compared to other traits, but can be potent on their own: you can have a persistent damage over time area (fire or negative), fast healing literally until you explode with life energy (positive), mass entombment (earth), mass drown (water), or, the most game breaking of all: a cool breeze ruffling the locks of your golden mane while you strike a heroic pose (air).

Morphic traits are quite exotic: usually one has the opportunity to tamper with Highly Morphic planes, such as Limbo. Some spells and effects allow you to mess with Divinely Morphic planes (all Outer Planes, for that matter). Here, take a sip:

Spoiler: Divinely Morphic
Specific unique beings (deities or similar great powers) have the ability to alter objects, creatures, and the landscape on planes with this trait. Ordinary characters find these planes similar to alterable planes in that they may be affected by spells and physical effort. But the deities may cause these areas to change instantly and dramatically, creating great kingdoms for themselves.

Now, I do encourage you, as the spellcaster player that you are, to think creatively while manipulating these traits – a lesson learned by all wizard players: with great powers, comes the reasonable social obligation not to smash the game into pieces smaller than your post-Saint-Patrick’s-walk-of-shame dignity – well, you’re not bound to strict formulas peculiar to Vancian magic system anymore. When you start messing with the building blocks of the game setting, you’re much closer to Mage the Ascension’s spellcasters – sans the whole Paradox and MIB is coming for you thing.

Fine, but how should you be doing all that, you ask? Well, good sir, I am glad you asked. No, really, otherwise I would be talking to myself, which is a sign of early dementia. I will be presenting below categories of effects that can be used to set up your planar tinkering or to weaponize it. In short, it all comes down to pierce reality through planar breaches, portals, rifts, bubbles, manifest zones, or planar superposition areas and then having their traits applied to the relevant area or locking people away for (un)safe storage/disposal.

One of the best mechanical abilities I have found - and the angular stone for all this research - was the Planar Bard substitution levels:

Spoiler: Planar Bard
Portal Dissonance (Su): A bard of 6th level or higher with 9 or more ranks in a Perform skill who selects this planar substitution benefit can use music or poetics to influence intraplanar and extraplanar portals, moderate or severe planar breaches, and other discrete passages between planes (complete planar breaches cannot be affected). The portal, breach, or other qualifying passage to be affected must be centred within 60 feet. The bard must know about the portal. Each round of the performance, he attempts a DC 20 Perform check. The bard can’t take 10 on this check. Success indicates that the bard can redirect the portal destination to the mouth of any other active portal or breach he has personally travelled through in the past 30 days. Redirection automatically fails if the portal chosen as the temporary endpoint is no longer active. Only creatures and objects are affected by redirection, not traits (which leak through planar breaches). Creatures that enter the portal from the bard’s side of the portal, or creatures that would otherwise arrive at the bard’s location through the portal, instead arrive at the endpoint of another portal chosen by the bard this round. The portal to which the bard redirects travellers continues to connect to its original destination; if a redirected creature attempts to go back through the bard-influenced portal, it doesn’t return to the bard’s location, but instead to that portal’s natural endpoint. The bard may keep up the dissonance for 10 consecutive rounds (this counts as one of the bard’s bardic music uses per day). This benefit replaces the suggestion bardic music ability gained by a standard bard at 6th level.

Getting any ideas with what I’ve said before about breaches in reality? Now, you do not need to be a Bard (I reckon it sounds a tad of an anti-climactic option for some people) in order to be an effective Planewalker. But you certainly do need to be a spellcaster. No surprise here. Going for Bard 6 is definitely encouraged as you can always supplement it with Sublime Chord and/or Ur-Priest. In the last section of this guide, a few build recommendations will be presented.

At each section, an introductory paragraph will briefly discuss the utility of the debated concept, accompanied by a few tactical suggestions.
For your convenience, the ever-popular colour code:

Red = only listed here for a vulgar display of thoroughness
Black = okay-ish
Blue = go for it
Golden = YAS

I. Bending space

These effects aim to create extra or nondimensional spaces where you can store friends and family, valuables, or even foes.
The most interesting usage of such spaces as prisons is to use the Transdimensional Spell feat (Complete Arcane p.84) to rain death upon semi-helpless targets.
A transdimensional spell has its full normal effect on incorporeal creatures, creatures on the Ethereal Plane or the Plane of Shadow, and creatures within an extradimensional space in the spell's area.

Spells:
Spoiler
Hoard Gullet (Sor/Wiz 1) DrM - 1 hour/level; 100lb./CL (max 1.000lb.) - shareable with familiar.
Rope Trick (Sor/Wiz 2) PHB - 1 hour/level; up to 8 creatures.
Portal Well (Brd 2, Clr 2, Drd 2, Sor/Wiz 2) CoV - 1 round/level; caster only - creates an extradimensional space between a portal's entrance and exit. The most basic tactics for a planewalker would be to create a portal to an extradimensional space, or to someplace nasty at higher levels, hide within a Portal Well and rain Transdimensional death on the other side - in such manner as to be protected from both your mark and its friends.
Familiar Pocket (Sor/Wiz 2) SpC - 1 hour/level - familiar only.
Shadow Cache (Brd 3, Sor/Wiz 3) SpC - 1 minute/level; small non-living objects only - 10% cumulative chance per day non-retrieved items are gone.
Astral Hospice (Clr 4, Drd 5) SpC - 1 day/level; 50cu ft. - castable on the Astral Plane only.
Pocket Cave (Initiate of Gruumsh 5) CoR - 1 hour/level; two 20ft. cubes/level.
Leomund's Secret Chest (Sor/Wiz 5) PHB - up to 1cu ft./CL; 5% cumulative chance per day after the 60th the chest is lost.
Mordenkainen's Magnificent Mansion (Sor/Wiz 7) PHB - 2 hours/level; three 10ft. cubes/level.
Maze (Sor/Wiz 8) PHB - Explicitly imprisons the target in an extradimensional space. Pairs nicely with Anticipate Teleport for when the spell ends, but then, what doesn’t?
Mordenkainen's Capable Caravel (Sor/Wiz 8) Storm - 1 day/2 levels; three 10ft. cubes/level + physical ship.
Pavillion of Grandeur (Creation 9) SpC - 1 day/level + 12 hours; five 10ft. cubes/level.
Genesis (Sor/Wiz 9, Creation 9) ELH - If understood to be able to manipulate time and magic traits, well, welcome to Tippy's! You could also get creative and roll an interesting prison plane for offensive uses.

II. Creating portal surfaces

This is how you shove people into the spaces between the planes. You should be taunting, goading, dominating, charming, commanding, reversing gravity, or pushing people through these portals. And then redirecting it to whatever makes you smile. No, really.
Please note all spells listed in the previous section "I. Bending Space" have interactable portal surfaces, thusly being subject to your planar rerouting (see section "V. Manipulating portal destination") method of choice - some of the effects below suggested create a permanent effect, that, when used as the end destination of planar rerouting methods could function as a "save point" or a backdoor into someplace where you would like to repeatedly visit (or invade).

Spells:
Spoiler
Alter Self or Polymorph + Assume Supernatural Ability - or - Metamorphic Transfer + any Host feat (see Complete Psionic p.59) into an Ether Scarab (Monster Manual II p.) for the ability to rip open a portal into any desired plane. Technically the earliest one could access planar travel (and quite the nice trick to have).
Shadow Well (Sor/Wiz 4) SpC - First direct offensive effect. Target's shadow becomes a portal to the Plane of Shadow.
Precipitate Breach (Sor/Wiz 5) PlH - Creates a minor planar breach (as per Planar Handbook p.152), which effectively makes planar traits bleed into a huge area. Seen the potential yet? - 10-minute casting time - so go nuts with Alacritous Cogitation, Uncanny Forethought, Runecasting, Glyph Seals, Supernatural Spell, emulating it through more powerful spells, or whatever have you. It has an amazing radius of 10d10ft.; starts off as a minor breach and gains more power each time you cast it again. Nice when served with a side of Repeat Spell and/or Twin Spell.
Create Crossroads and Backroad (Drd 7) MoF - Unlikely to ever see any combat use, due to 1-day casting time and 3.500XP component, but it has a nice fluff and cost-benefit, for when setting up the party HQ. Furthermore, it creates a naturally occurring portal, which is therefore not negated by magic-denying effects. One of the few ways to create a "save point" mechanic through portal usage (see section V.).
Reality Maelstrom (Sor/Wiz 7) MotP - Now, this is a big one! Everyone in a 5ft-radius/level emanation must make a Will save every round or be tossed into another plane. People in a 10ft-radius/level must make a Reflex save or be sucked into the primary area, which, then subjects those dragged in to Will saves. Fun bloody times.
Black Blade of Disaster (Sor/Wiz 9) SpC - The spell calls out the blade as being a planar rift. Not sure what benefits one could reap from manipulating the destination of it. It can't normally be persisted and lasts for Concentration, Max 1 round/level - so if you can juggle it past your GM, as it is explicitly a planar rift, it could arguably be used as the chassis for Planar Breaching.
Elemental Swarm (Air 9, Drd 9, Earth 9, Fire 9, Water 9) PHB - Although it explicitly states that you pop open a portal to an elemental plane, there are no hard rules regarding this particular aspect of this spell. Still, for the sake of completeness, we are listing it - might, therefore, require DM's adjudication.
Armaggedon (Sanctified 9) BoED - See Elemental Swarm.
Reality Maelstrom (Sor/Wiz 9) SpC - Even though the SpC version is the most recent, and thus the valid entry, there is a HUGE upgrade to the spell's area in this version: 20ft-radius/level for primary area and 40ft-radius/level for secondary area. Have a wee chat with your DM and see if you can pull a 7th level version as a "lesser" Reality Maelstrom.
Gate (Clr 9, Sor/Wiz 9) PHB - Go win the game and forget about silly planar nonsense.
Precipitate Complete Breach (Sor/Wiz 9) PlH - Remember Precipitate Breach? This is him now. Feel old yet? As is, the 9th level is not worth it. I mean, 4-level bump, 1.000XP and 1.000gp component? I'd rather undergo vasectomy through rusted scissors and a hammer. If you have any means to circumvent such costs (looking at you Dweormerkeeper), then this becomes gold.
Mirror Walking (Clr 5, Sor/Wiz 7) MotP - You make a mirror into a portal to the Plane of Mirrors. This one is tagged red if you pass through the portal yourself, as a copy of you will be pitted against yourself when you reach the other side of the portal. The spell Target section, however, indicates creature touched. If you can cast this on someone and then shove them through a mirror, then this becomes gold. Suggested by ShurikVch.

Utterances (haha yes):
Spoiler
Conjunctive Gate (Lexicon of the Perfected Map 4) ToM - For the sake of completeness. This is a rather nice effect, as far as anything related to Truenaming can be dubbed nice.

Items:
Spoiler
Cubic Gate (DMG) 164,000gp - Each side of the cube is tuned to a different plane (randomly generated if found as treasure). Activating the cube will pop a gate to a random location in the corresponding attuned plane. The secondary activation planeshifts the user and all adjacent characters to that particular plane.
Orrery of the Planes (Eberron Campaign Setting p.271) - Jackpot! For 50,000gp this 1-foot diameter model of the planes creates a manifest zone for 24 hours in a 60-feet diameter area once per day. The effect ends, however, as soon as the orrery is moved.
Passage (Oriental Adventures p. 127) 32,400gp Weapon Enchantment - Once per day, the wielder may cut open a portal as Plane Shift spell, which remains open for 1d4 minutes.
Dimensional Chalk Holder (A&EG p.131) 22,950gp - Allows for the planar travel aspect of the Gate spell 1d4+1 times before crumbling to dust. Interestingly enough, there is no size limit to the circle that makes up for the edges of the portal. After issuing a mental command, it takes the Holder 1 full round to draw up the Gate. If your DM does not frown upon the reuse of charged items via, say, Astral Projection or Lucid Dreaming, then this is bumped into Gold category.
Ethereal Tapestry (Manual of the Planes p.59) 47,520gp - While not exactly practical, taking one person about 10 minutes to set it up, the tapestry is about the size of a normal doorway (8ft. tall and 3ft. wide). At 47k doesn’t feel like a bad investment, if you have enough time to prepare.
Mirror of Mental Prowess (DMG p.262) 175,000gp - Allows to user to cast clairvoyance on places even across planar boundaries and to create a portal to said locales. For all that, it is quite the bulky item to carry around and set up properly for combat use (suggested by Bronk).
Mirror of Translocation (Dragon 305, p.66) 153,200gp - A pair of mirrors that teleport you from one to the other even across planes (suggested by Bronk).

Feats:
Spoiler
Mastery of Madness (Player's Guide to Eberron p.126) - Whenever you summon a celestial or fiendish creature by the means of any spell, spell-like ability, or magic item, you can instead summon a pseudonatural version of that creature. Now, the good part: whenever you use this feat, you must succeed on a CL check DC 15 + spell level to avoid opening a *small temporary rift* to the Far Realms/Xoriat. This affects the spell as if it were cast on a plane with the wild magic trait. Now, I know the rift part is not mechanically explicit, rather merely fluff, but, well, this is a roleplaying game, goddammit, we should explore options!
Create Portal (FRCS p.34) - Now, as far as creating magical items this is a tad expensive. It is, however, one of the few ways to implement a permanent portal-end of your choosing, in such manner as to create a "save point" (see section V.)
Portal Mastery (PGtF p.42) - I would take this one as an improvement over the last item. Not only does it cut the costs for creating portals in half, it also sports a secondary effect that allows you to stabilize malfunctioning portals.

Monsters:
Spoiler
Sharn (Anauroch p.154) - Can create up to 3 mobile 3-foot diameter portals and cast spells through it. The portals are explicitly ethereal in nature. Not sure how one can capitalize on that, apart from being a Sharn, though.
Ether Scarab - See spell section above.

Things(?):
Spoiler

Flux Slime (SRD or ELH p. 107) is a nasty breach in the planar fabric which, amongst other things, radiates an (Ex) Antimagic Field, is actually a planar breach of sorts, and explodes in a huge area if destroyed.
Originally Posted by Darrin
you can use a Chaos Flask (100 GP) to create a bit of Flux Slime. This is a... plant/ooze/mold... sorta? That generates an anti-magic field, and also explodes if you do anything to it, like wiggle it or expose it to sunlight. If it does explode, it could give you a permanent mutation. However, while it's not exploding... it's a physical indicator of a leak between the planes, which is similar to a planar breach or planar portal of sorts. So if you've got an ability that allows you to redirect or manipulate where a portal goes... maybe you could exploit this for planar travel purposes?
The Aukaraks (Secrets of Sarlona p.144) - This planar oddity is described as a free-floating planar breach. Takes 1d10 minutes to fully manifest and, in game terms, is a naturally occurring weather-like manifest zone. Arguably, "mundane" hazards, so there might be a way to replicate this.

III. Tossing people around, hopefully through planes or portals

I will refrain from citing all pushing/pulling effects like bull rush or Telekinesis and will, instead, focus on forceful teleportation, as it sets up a rather nice interaction with Anticipate Teleport, which is used as a low-carb replacement for messing around with Time Traits – thus avoiding having your nose caved in by means of having the Planar Handbook smashed repeatedly against your face. DMs are quite wild these days.

Spells:
Spoiler
Baleful Transposition (Sor/Wiz 2) SpC - Close range, 2 targets up to Large size swap places. Will negates.
Dimension Hop (Duskblade 2, Sor/Wiz 2) PHBII - Teleports touched target up to 5ft./2 caster levels. Will negates.
Scattering Trap (Sor/Wiz 3) PHBII - One 5ft. square/2 levels teleports passing creatures 1d6 squares in a random direction. Reflex negates.
Desert Diversion (Sor/Wiz 4) Sand - Affected target is redirected to a previously determined wasteland area whenever subject to teleportation of planar shifting spells and spell-like abilities.
Dimension Shuffle (Sor/Wiz 5) PHBII - Close range, one target/level, teleported up to 30ft. in any direction. Will negates.
Slide (Sor/Wiz 1) Mini - Target moves 5ft. Will negates. Do note Slide and its older brother lack the [teleportation] tag, but I’m fond of Will-targeting spells.
Slide, Greater (Sor/Wiz 2) Mini - Target moves 20ft. Will negates.
Trobriand's Baleful Teleport (Sor/Wiz 6) Waterdeep - As teleport, except it sends only the target creature to the intended location.
Translocation Trick (Sor/Wiz 6) SpC - Medium range, swap places and appearances with target. Will negates. This one can be quite confusing if your party is not expecting it.
Nybor's Joyful Voyage (Sor/Wiz 7) here - Touched target is teleported 1d100 miles in a random direction. Will negates the teleportation but target still takes 3d6+1/level. Even if the target is shot far beyond your Anticipate Teleportation or immediate BFC spells, 1d100 miles skywards or underground and, well... someone will have a bad day.
Halaster's Teleport Cage (Sor/Wiz 9) Waterdeep - Impractical for spontaneous combat, as its casting time sits at 10 minutes. Area is pretty impressive (one 10ft. cube/level) and it is permanent. Nice if you're expecting a huge battle and have time to prepare.
Scramble True Position (Brd 1, Clr 1, Sor/Wiz 1) ToM p.258 - Requires a stupid Truenaming check (DC 15 + [2x target's CR]), but it will teleport people in a 10-ft. radius spread up to two squares in random directions with no save.

Monsters:
Spoiler
Bar-Lgura (Fiendish Codex I pg.30) can greater teleport targets away as a supernatural ability. At meagre 6HD Outsider type combined with Polymorph, or Alter Self + Reserves of Strength, and Assume Supernatural Ability (Savage Species) can spam an offensive Greater Teleport at-will. Might be an interesting choice for Planar Binding.
Ethereal Ooze (Fiend Folio p.63) - A 12HD ooze that can etherealize (Su) engulfed creatures up to Large size.
Maulgoth (Fiend Folio p.123) - A 20HD aberration that can Ethereal Jolt (Ex) as a touch attack. Targets must save vs. Will DC 29 or be forced onto the Ethereal plane.
Umbral Banyan (Manual of the Planes p.171) - A 15HD plant that can plane shift (Su) grappled foes into the Plane of Shadows for 5 rounds - No save. The Banyan is Huge and sports a +28 grapple modifier, plus a couple other goodies.
Xill (Monster Manual pg.259) - A 5HD outsider, and, as such, well within the realm of Alter Self, sporting Planewalk (Su) onto the Ethereal as a move action; may take a willing or helpless creature along.

Items:
Spoiler
Chardalyn here, or Shalantha's Delicate Disk (Sor/Wiz 6 - Lost Empires of Faerun) allow one to use personal-range abilities on enemies, so you could add vanilla harmless teleport effects to this list. Or plain simply be silly with Tenser's Transformation or Transcend Mortality.
Windsong Towerkin Ring (Anauroch p.149) - It is a minor artefact alright - but it negates the range limit from any spell, spell-like or supernatural abilities with a [teleportation] tag.

2. ## Planewalking – a guide for bending time and space

IV. Locking a portal and/or impeding planar movement

For preventing escape from your extradimensional spaces, or impeding someone from following you. A selection of spells for warding a portal against intrusion is added for your convenience.

Spells:
Spoiler
Arcane Lock (Sor/Wiz 2) PHB - Although *really* niche, adds 10 to a Gatecrasher's DC to break through your portals.
Dimensional Anchor (Clr 4, Sor/Wiz 4) PHB - Bear in mind this is a ray effect, so you might want to throw it in early or via Transdimensional Spell. Absolutely ruins an extradimensionally imprisoned guy's day. Or yours, should you need to pull a Brave Sir Robin sort of tactics.
Shadowblast (Clr 4, Drd 4) SpC - Closes portals to the Plane of Shadow.
Portal Barricade (Portal 5) Und - Shuts down a portal for 1 hour/level.
Gate Seal (Brd 6, Clr 6, Sor/Wiz 6) FRCS - Permanently (not an instantaneous effect, mind you) shuts down a portal.
Seal Portal (Sor/Wiz 6) SpC - Now, really, you just swap word order and call it a day?
Forbiddance (Clr 6) PHB - Lucky you, this bad boy sports 6 rounds worth of casting time. But is (a). Permanent; (b). 60ft-cube/level; (c). hostile to you. Worth noting it does not mention anything about extradimensional spaces - your DM might object such vulgar display of lawyering, however.
Dimensional Lock (Clr 8, Sor/Wiz 8) PHB - When Dimensional Anchor meets Super Mario's growth mushroom.
Zone of Respite (Clr 5, Sor/Wiz 5) SpC - Much less problematic Forbiddance-like effect, though it takes 2 rounds to cast and is a 20ft. emanation centred on the caster.

Spell wards - Better cast in advance or through items (to circumvent casting time constraints):

Ghoul Glyph (Hunger 2, Sor/Wiz 2) SpC - Unless target has mettle, it is paralyzed for 1d6+2 rounds.
Glyph of Warding (Dwarf 3, Rune 3, Wealth, Clr 3) PHB - Subjects trespassers to 5d8 damage or 3rd level spells.
Glyph of Turning (Clr 3) Ghost - Turns or rebukes trespassing undead
Fang Trap (Clr 4, Sor/Wiz 4) SK - Immobilizes target for 1 round; Fortitude or 1d4 piercing/bludgeoning per caster level.
Runic Marker (Clr 4) CoV - Restricted to the Blast Glyph effect, but you save on the material components.
Glyph of Warding, Greater (Rune 6, Clr 6) PHB - As Glyph of Warding, but up to 10d8 or 6th level spells.
Guards and Wards (Sor/Wiz 6) PHB - Interesting for a permanent extradimensional space or demiplane.
Symbol (various) PHB - The material components of assorted symbol spells make them a poor choice, overall.
Elder Glyph of Warding (Clr 9) LoM - As Glyph of Warding, but up to 30d8 or 9th level spells.

Items:
Spoiler
Weirdstone (PGtF p.124) 250,000gp - Blocks all spells, spell-like, supernatural or extraordinary abilities, or any other effects that mimic astral and ethereal travel, divination [scrying], and conjuration [teleportation]. In. A. 6-mile. Radius. Do note you can create such effects if you target an area *outside* the Weirdstone's area of effect - so it would block teleporting + anticipate teleportation against foes in your immediate vicinity, but would not impede casting them into the Abyss, for instance.
Portal Demolisher (Underdark p.75) - A minor artefact (luckily for us), which destroys portals with no save allowed.
Corporeal Lodestone (Dragon 342, pg.68) 39,000gp - Prevents travel to and from the ethereal within a 20ft. radius. Although easy to carry around physically, it can never leave the material plane (suggested by Bronk).
Extradimensional Anchor (Dragon 306, p.66) 112,000 gold - Emanates a continual dimensional within a 40ft. radius (suggested by Bronk).

Shenanigans
Spoiler
Solidified Positive Energy (Bastion of Broken Souls p.19) This bad boy "is unbreakable, impenetrable to magical/psionic entry, and unresponsive to magical or psionic methods to even learn about the interior. Its impenetrability means that creatures (and PCs) on the inside cannot summon aid with summoning or planar ally spells (no calling or summoning spells work within the Bastion). Only a deity could conceivably bring sufficient force to bear and physically force an entrance — but no deity would attempt such folly, in rightful fear of the Ban of the Unborn. All other spells work normally, though divination and commune spells dealing specifically with the Bastion remain as unhelpful as ever".

V. Manipulating portal destination

The first steps on the long road of bending time and space to your will start here – the meta here is to allow you to have an active role on the destination or coterminous effects of portals and rifts you create, if you did not have the power to set up the destination in the first place.

Spells:
Spoiler
Portal Stabilization (Portal 1) Und - Makes an unstable portal 30% more reliable.
Scramble Portal (Sor/Wiz 4) SpC - Randomizes the destination of portals for 1 round/level. Nice for masters of time and space that skip those healthy Bard levels
Portal-to-Portal Redirect (Portal 6) Und - As Scramble Portal, but you may choose the destination. Pretty much like Planar Bard 6.
Portal Reformat (Portal 8) Und - Adds or removes an activation key to a permanent portal.

Class abilities:
Spoiler
Planar Bard substitution level 6 (Planar Handbook p.29) – The pertinent ability was quoted back at the preamble. If you have read through all of this, you will probably follow Palpatine’s command and DO IT.

The Create Portal feat(FRCS pg.34) or the Create Crossroads and Backroad (Druid 7, MoF pg. 86) spell when combined with Portal Dissonance could create a "save point" mechanics of sorts; even though both are a tad expensive, they should be worth as either a standalone tool for an impromptu (albeit permanent) backdoor access into an enemy stronghold, or as a portal detour back to the party's HQ. A "save point" in both cases, as they would anchor the end of a portal, thus constituting valid targets for Portal Dissonance - idea inspired by Uncle Pine's contributions.

VI. Manipulating immediate planar surroundings

Oh, yes, here we are, the crème-de-la-crème of this whole business. This is where your DM will probably start to get angry at you: Planar-manipulating effects mean you have a spectacular control over the battlefield. Once you have mastered the proper planar destination via “Manipulating portal destination” methods, now it’s the time to learn how to superpose planar traits in your immediate vicinity.

Spells:
Spoiler
Perinarch (Drd 4, Sor/Wiz 4) PlH - Controls a radius of raw Limbo up to close range for some nice effects - 3d10 fire damage/round; making maximum speed in the area 5ft/round; creating an impassable barrier or a trap of solid stone around foes. Nice when paired with Precipitate Breach or Planar Bubble.
Planar Bubble (Clr 7, Sor/Wiz 7) SpC - Hail to the king! This one emulates planar environment around you as if it were your native plane. Couple with some creative Outsider type + Polymorph effects for expanded fun, or Planar Chasuble (see below). Pair with Extraordinary Spell Aim and/or Sculpt Spell and have a go at the next section.
Intensify Manifest Zone (Clr 7, Drd 7) FoE - Now, this one is tricky. First the 8-hour long casting time, then the 500 XP price tag. But is it worth it? Well, if you already have a Manifest Zone going you could have a planar trait leak throughout the area. Manifest Zones (Eberron Campaign Setting pg.94) are places where two planes become coterminous and spontaneously begin manifesting planar traits from each other. I don't know you, but I'm thinking Precipitate Breach. Added bonus: Intensify Manifest Zone's duration is permanent, so, suppose we stacked this on top of a Precipitate Breach spell... is it permanent now? *mind goes boom*
Planar Perinarch (Drd 9, Sor/Wiz 9) PlH - Like Perinarch, but you may cast it on highly morphic or divinely morphic planes - which is pretty much all Outer Planes. So, well, it pairs nicely with Planar Bubble (everything does, I know). Even on its own this spell shines in planar campaigns.

Psionic Powers:
Spoiler
Note: I have avoided psionics thus far, not because I dislike the mechanics, it is more a matter of flavour and that the powers I have read so far, sort of mimic spell effects. However, if someone does have an interesting or revolutionary psionic-planes interaction, I am all ears.

Anchor Plane (Psion 8) FoE - This one power merits special attention. It effectively borrows a planar trait from a chosen plane. Do note it is an instantaneous duration [Metacreativity] power, which means it could be cast from the Ethereal (see the Avoiding AMF/dead magic zones and planes section), recreating magic in an otherwise dead magic plane. Mind the 750 XP cost, however. Do note that under Magic-Psionic transparency, a Wish or Miracle might be able to replicate this effect; barring that, Psionic Tattoos or Piercings (haha yes) (http://archive.wizards.com/default.a.../psm/20031225a) will do the trick.

Skills:
Spoiler
Lucid Dreaming skill (MotP pg.203) - Do not Planar Bubble and Lucid Dream your way through the campaign. Seriously.

Incarnum:
Spoiler
Planar Chasuble (Magic of Incarnum p.83) - The soulmeld by itself (easily acquired by the feat Shape Soulmeld) makes you a native to any plane of your choice which matches your alignment. Planar Bubble called, it said you two should talk.

Monsters:
Spoiler
Limbo Stalker (Planar Handbook p. 126) - 8HD Magical Beast. Can wrap itself in an area of controlled Limbo as a DC 16 Wisdom check as a free action and vanish. This ability is named "Limited Invisibility" and is Extraordinary; the effect only ends if the creature moves or attacks.

Gouda:
Spoiler: Don't
Planar Shepherd (Faiths of Eberron p.105) - Don't think you need any explanation here.

VII. Recommended portal planar destinations

If you are not content - and you should not be - with simply stating whatever traits you want to leak through your portals, I do advice you to take a gander at these beauties. Book a trip to Sigil and go sight-seeing at these marvellous portals.

Do note there is a plethora of planar hazardous anomalies (such as the ones listed in Fiendish Codex I, p.112) that could potentially be weaponized. Knowledge (the planes) and Gather Information are, as ever, your friends; so, boost the hell out of your skill modifiers and go find yourself a portal that leads exactly where you want it to. The planes are infinite after all, you are bound to find what you are looking for, somewhere.

An interesting read is "A Trip to the Market" from the Savage Tide Adventure Path, DUNGEON Magazine #148, p.57, which should help DMs to populate a proper market with extraplanar tuning fork costs – which seem to imply that you can indeed Plane Shift, and therefore use any other similar planar hopping method, to any particular destination you know about or can access:

Spoiler: A Trip to the Market
“Particularly common in the Broken Reach market place are the metal rods used as focus components for plane shifting to different layers of the Abyss. Rods for relatively well-known layers such as Pazunia, the Demonweb, Gaping Maw, Thanatos, and Shendilvari sell for 3,000 gp. Rods for more obscure layers, such as Twelvetrees, Shedaklah, and Androlynne sell for 9,000 gp. Rods for truly remote realms, such as the Dreaming Gulf, the Blood Shallows, or Zionyn sell for 15,000 gp. Certain rods are particularly rare, as the Abyss itself resists allowing travel to its deepest and most important layers. This includes layers like Ulgurshek, Woeful Escarand, and the Wells of Darkness; these rods cost 40,000 gp apiece”.

I will only list mechanically interesting effects rather than a comprehensive list of all planar quirky spots.
As a last note regarding planar locations, I should reinforce that all Planar Touchstones (Planar Handbook, Sandstorm & a few others) are all obviously good choices, both for their mechanical effects and for their mini-quest spawning potential. As for Magical (and Psionic) Locations, I have only listed non-vanilla spots, but arguably one should be able to reach the ones in DMGII and Complete-whatever series just fine. With an extraordinary mention to:

Naja Fountain (Serpent Kingdoms, pg. 154) - Located in the city of Ss'thar'tiss'ssun, which instantly grants a +3 increase to arcane caster level.
Temple of Mystra (Faiths and Pantheons, pg.51) - "Any spell cast within [a temple of Mystra] by her clerics can benefit from one metamagic feat without needing to take up a higher-level spell slot; the benefit ends if the recipient leaves the location of the temple."

Dungeon Master’s Guide I
Spoiler
Misty Cemetery, Ethereal Plane (p. 152) - Pretty much what the name implies, inhabited by packs of ghosts; ringleaders are listed as a Fighter 12, a Fighter 5/Cleric 9, and a Sorcerer 16.
Silver Sky, Astral Plane (p. 154) - And endless stretch of silver haze, dotted with colour pools (one-way portals; 30% of the time, however, they function both ways). It takes 1d4x10 hours to find a colour pool that leads to a particular plane.
Cloud Island, Plane of Air (p. 155) - A semi-solid sort of cloud, that can be traversed with some difficulty by flying creatures (which are treated as having burrow speed 10). If your DM deems Planar Binding chain wishing a tad... anticlimactic, here's a fine gem: if a party can capture (defeat without killing) the noble djinn that dwells in the centre of the Cloud Island, it grants the party 3 wishes. How's that for spontaneous side quests?
The Great Dismal Delve, Plane of Earth (p. 155) - And I quote: "It is rumoured that somewhere within the Great Dismal Delve is a freestanding portal to almost every secret location within the D&D cosmology".
City of Brass, Plane of Fire (p. 156) - It's a planar metropolis, so, well, go sight-seeing or something.
Sargasso Doldrum, Plane of Water (p. 157) - "A spherical tangle of kelp and seaweed a mile across". Even if a character possesses a swim speed, it takes 2 squares of movement to traverse each square of kelp. Line of Sight is limited to 30ft. and everything beyond 20ft. enjoys concealment. The Sargasso is infested with dire sharks who "attack in great hunting schools without regard to their own safety".
Voidstone Field, Plane of Negative Energy (p. 157) - Well, ya know spheres of annihilation, right? This is the stuff they're made of. Each round of contact warrants a DC 25 Fortitude. Fields usually sport 3d6 stones, that take up a square each, alongside 1d4 large stones, that are 10ft in diameter. Every round at initiative count 0 each voidstone moves 1d3 squares toward the nearest living creature. The good news? Nightwalkers live among the voidstones. The bad news? We've booked you a trip there.
Howler's Crag, Pandemonium (p. 160) - Anything yelled aloud from the top of the Crag finds the ears of the intended recipient, no matter where on the multiverse they are. That's a pretty dramatic way to send a message, so you know your character will definitely climb it to insult their Wizard School teachers. Also, Pandemonium wind.
Sand Tombs of Payratheon, Carceri (p. 161) - Welcome to a ruined city housing 24 HD burrowing gorgons, mummy lords, and a plethora of hungry undead. Did I mention there's a titanic sandstorm 1d4 hours away?
Thuldanin's War-Cubes, Acheron (p. 163) - If you manage to keep something here for long enough, creatures and objects in Thuldanin have a 1% cumulative chance per 30 days of spontaneously petrifying into stone (no save) - only reversible through miracle or wish.
Fortress of Disciplined Enlightenment, Mechanus (p. 163) - The headquarters of the Guvners. If you need to research something, this is the place. Just fill your forms.
Mount Clangeddin, Arcadia (p. 164) - And I quote: "weapons of any price can be bought (but not sold) here".
Empyrea, Celestia (p. 164) - Nonevil, nonchaotic characters can get free healing (damage, disease, or negative levels). Cures for more elaborate sort of ailments can be achieved through ritual combat.
Mottlegrasp's Orchard, Bytopia (p. 164) - More spontaneous quest potential: some ability-enhancing wholefood shenanigans (equivalent to tomes and manuals) guarded by a level 18 gnome wizard. Figure one might either rob or work for the little guy.
Heroic Isles, Elysium (p. 165) - When you positively must get an autograph from a dead hero of the past.
The Spire, Outlands (p. 166) - Gotta kick some divine-ranked arse? Here's your place.

Manual of the Planes
Spoiler
Psychic Storms, Astral Plane (p. 51) - This can - and will - seriously ruin everyone's day.
Dead Deities, Astral Plane (p. 51) - My favourite planar tourist trap. For when you positively need to take a **** inside your theist friend's soul.
Special Discoveries, Plane of Earth (p. 72) - Dig for long enough and you're bound to get some gold. If abused, however, your DM might go Minas Moria on you.
Magma Rivers and Firefalls, Plane of Fire (p. 76) - Exactly what the name suggests.
Currents, Whirlpools, and Bores, Plane of Water (p. 78) - Cracking open your copy of Stormwrack, are you?
Energy Bursts, Plane of Positive Energy (p. 83) - If you're in the Elemental Plane of Positive Energy, you rack up temporary HP every round and when you reach double your maximum hit points you explode in an intense cascade of glitter and celery juice. Energy Bursts locations give you that extra pump you need to reach your goals. And, oh, yeah, they blind you for 1d10 rounds if you fail a Fortitude DC 24 check.
Animating Fields, Plane of Positive Energy (p. 83) - Every round there's a 50% chance that one object in each person's possession animates and attacks. The animation lasts for as long as one stays within the field (which ranges from 150 to 1,500ft.), plus additional 2d6 rounds after the visitor leaves the area.
Spawning Stone, Limbo (p. 96) - A 45 HD death slaad with several levels of fighter and sorcerer *guards the Spawning Stone at all times against potential nonslaad visitors*. Now, slaadi are not exactly the most common foes one goes around bashing through the multiverse, is it?
Citadel of Slaughter, Pandemonium (p. 99) - The seat of Erythnul's power is bound to be the suicidal planewalker's wet dream.
Apothecary of Sin, Carceri (p. 105) - If you need a poison, toxin, or whatever, you can find it here.
Bahamut's Palace, Celestia (p. 134) - Sort of self-explanatory, I believe.
Library of Lore, Outlands (p. 150) - If a spell was ever created, this place has a copy of it. I’m not gonna say everyone whose class rhymes with ‘izard’ or ‘chvist’ wants to visit this place, but it is a fair assumption.
Neth, the Plane that Lives (p. 154) - If fighting a dragon is bad enough, picture fighting the plane you're standing on.
The Observatorium (p. 156) - You can scry on the whole multiverse from here. Mystra's bath tub? Check. St. Cuthbert's browser history? Check. Corellon's prom queen dress? Why would y… ok, Check.
Region of Dreams (pg.201) - Flowing Time, Highly Morphic, and no spells slots used whilst in the Region of Dreams are actually expended. Splash this with a bit of Lucid Dreaming (p.203) and watch the fun begin.
The Plane of Mirrors (pg.204) - A mirror-self is created somewhere else on the Plane every time someone waltz in. This mirror-self is identical to the original character in every way, except for having the opposite alignment and a murderous disposition towards the original one. Good luck, Mirror-Tarrasque.
Spirit World (p.206) - All divine spells are extended and empowered.
Elemental Plane of Cold (p.206) - All cold descriptor spells and spell-like abilities are maximized, and all spells that use water are extended. Also, all fire spells are impeded.
Elemental Plane of Wood (p.207) - All spells that use or create water (including those of the Plant domain) are extended and maximized.
Temporal Energy Plane (p.208) - For when you positively, definitely, objectively, morbidly hate your DM.
Plane of Faerie (p.210) - Oh, boy, all arcane spells are, repeat with me: maximized, extended, and empowered. Now, there's this pesky Flowing Time trait that will **** you many times over. If only we had a workaround... oh wait, we have! Check out Ritual of the Timeless Soul, under section X. Utility and miscellany.
Far Realm (p.211) - LOL, yes, please.
World Serpent Inn (web enhancement) - Well, aint this a little gem? Timeless, Minor Positive, all Magic is impeded, Damage Reduction 10/-, and natural see invisibility. A nice party buff if I've ever saw one. Bonus points for harbouring two-way portals for random demiplanes and one-way tickets for random planes.

Fiendish Codex I
Spoiler
Pits of Pazunia (p.110) - 1d100 of pure dead brilliant nastiness. Seriously, go take a look at this chart.
Aldinach's Egg (p. 115) - Imposes the half-fiend template on good-aligned creatures. Even though making your enemies stronger is not exactly Sun Tzu material, if you are fighting good creatures you are most likely playing an evil campaign - and much like STDs and teenager youtubers, Evil wins by being spread around.
Lakes of Molten Iron (p. 116) - You know all that jazz about conjuring lava and how improbable it is that people jump onto it? Well, there you go. 1d10 fire damage per round if you are within 100 yards of it, 2d6 fire damage per round of exposure, and 20d6 fire damage per round if you want to go for a swim.
The River of Salt (p.120) - Creatures within 10ft of the river are subject to suffocation (DMG p.304) from choking on the dust generated by the grinding salt crystals. Submersion in the crystal flow translates into 6d6 bludgeoning damage per round.
Zrintor, the Forest of Vipers (p.120) - It is described as *ahem* "an impossibly large forest of viper trees", which once per round makes a single melee attack at +13, with a reach of 10ft, dealing 2d6 damage, with a Poison riding effect (DC 14 1d6 Dex/1d6 Dex). Failing both checks paralyzes the target for 24 hours. Each tree has a Hardness of 7, Break DC 30 and 300 HP and usually appears in groves of 1d20+4. So much for Profession: Gardener.
Crystal Tower of the Yochols (p.124) - This one lies within the Demonweb Pit layer. By the name of the locale and of the layer, I hope you have figured by now that this is where you send any elf that might antagonize you.
The Emblem of Abrogard (p.125) - Evil spells are empowered and extended.
The Labyrinth of the Arachne (p.125) - 100-foot-square maze with no known exit and filled up with spidery abominations. Yum.
The Venonsphere Lens (p.126) - Arguably could contain a portal to anywhere in any Material Plane.
The Ulgurshek Orifice (p.126) - When you just want people to shove it. This layer is actually a living creature so large, but so large, that yo momma is envious. It is said that Lolth's minions "use the Orifice as an efficient garbage sluice and prisoner disposal".
The Grand Abyss (p.133) - You know the thing this plane is named after? Well, this is it.
Twelvetrees (p.134) - Evil spells are maximized and extended.
The Iron Wastes (p.135) - The weather ranges from Cold to Scottish Winter (see Cold Dangers, DMG p.302 + Frostburn).
Svafnir's Lair (p.136) - The Hobbit, white dragon version.
The Blood Dunes (p. 143) - The weather ranges from Severe Heat to Brazilian Summer (see Heat Dangers, DMG p.303 + Sandstorm).
The Forest of Poisoned Dreams (p.144) - If you actually spend a week in this place and succeeds on a Profession: Herbalist DC 25, you get +2 inherent bonus to Wisdom. Failing the check means a Fortitude DC 20 or die a horrible death.
The Endless Maze (p.152) - The title alone should suffice.

Spoiler: Web Enhancement

You can find it here, and I can guarantee you that any spot you pick will be as pleasant as watching George Clooney's Batman.

Places of special interest, however, include :
Spirac - You can find a fountain of youth that rejuvenates its user by 1d4 x 10 years.
Durao - Where the abyssal hordes assemble for the Blood War. "Few mortals are allowed to live once they have glimpsed the mighty tanar'ri war machine at its very heart".
Zionyn - For those with an Alien the 8th Passenger kink.

Fiendish Codex II
Spoiler
Maggot Pit (p.38) - A pit of goo, 1,000ft. in diameter, anyone fully immersed in it must roll Fortitude against contact poison (DC 25 1d6 Wis/1d6 Wis).
River Styx (p.39) - Remember when you wake up next to someone (or something) and you really wished you could whisk away those memories forever? Well, contact as brief as immersing your hand or foot into the Styx prompts a Fortitude DC 25 or suffer from amnesia for 3d6 days. If more than half the character's body is immersed, DC increases to 30, and to 35 if fully immersed.
Draukari (p.39) - Initial exposure prompts Fortitude DC 25 or the character is sickened for 1d4 minutes.
The Garden of Delights (p.43) - An illusory prison from which one willing to leave must succeed on a Will DC 30. Every failure stacks a cumulative -1 penalty to the characters Will saves.
The Pit of Flame (p.51) - Creatures immune to fire are beset with convulsive agony and are unable to think or take any other action, except to attempt escape. Creatures not immune to fire take 9d8+9 points of damage per round. Do note that this damage is not stated to be fire damage.
The Shriver (p.52) - A Magical Location valued at 30,000gp. If you can endure a ton of damage and manage some good Fortitude and Will saves, you could actually score some nice bonuses.
Hall of the Vanquished (p.57) - A quaint museum of souls. Folks slain by weapons enchanted with the "Bind to Hell" spell presented alongside (Cleric 5, [teleportation]) have their souls - or in case of outsiders, their whole body-soul thingmie - bound in a hellish Madame Tussaud's, preventing their resurrection. Now, this might not be the most effective way to permanently dispose of a recurring villain, but it is REALLY cool.
Pillar of Geryon (p.58) - Another Magical location, this one valued at 36,000gp. Your unarmed strikes now deal 1d10 and have a +3 enhancement bonus (+6 against chaotic or good outsiders). Best of all, once per round one of your unarmed strikes can be delivered as a touch attack.
Ankhwugaht, the Realm of Set (p.59) - And I quote: "Living mortals entering Ankhwugaht must somehow disguise the tell-tale taste of vitality on their breaths or be immediately swarmed by Set's horde of mummies, liches, and fiendish jackal-headed warriors".
Lakes of Bile (p.63) - For every round spent in the area, characters must make a Fortitude DC 13 or take 1 point of Constitution damage.
Venom Lake (p.63) - This lake produces Deathblade poison (injury, DC 20 1d6 Con/2d6 Con), worth 1,800gp per dose. So... free money?
Lake Verminmaker (p.63) - This lake produces Verminmaker, which transforms its imbiber into a randomly chosen vermin, as if affected by baleful polymorph (Fortitude DC 17 negates). Note that this is NOT a poison, and seems to work in an antimagic field, given this is tagged as a "substance" worth 300gp per dose.
The Frother (p.64) - Fiendish bacteria fiercely attacks fully immersed characters for 15d6 damage or partially immersed characters for 8d6 damage per round.
Ribcage Mountains (p.64) - Covered in "poisonous goo" (contact, DC 25, 2d4 Con/2d4 Con).
Malagard (p.66) - To embark on a journey to any destination more than 250 away from his present location, a character must attempt a DC 25 Will. Failure means he procrastinate for at least one hour, when he may attempt a new save.
The Carnival Eternal (p.67) - Mortals gazing into one of the places' many mirrors must succeed on a DC 30 Will or be affected by a suggestion that translates into an corrupt or obeisant act.
Cania (p.69) - 10d6 cold damage per minute (no save).
Toxic Zone (p.70) - Fortitude DC 25 every 10 minutes or inhale poisonous air (1 Con/1d4 Con) + Cania cold damage (see above).
Gorge of Slaughter (p.74) - After 10 minutes all characters must attempt DC 25 Will save. All creatures failing this save immediately gang up to attack those who succeeded on it. A new round of saves is required every 1d4 hours.
Spectre Gorge (p.75) - Mortals killed here cannot be raised or resurrected but will return as spectres after 1d12+4 days to attack any former colleagues present at their demise.
Crevasse of Eternity (p.75) - You fall. Until you finally die of thirst or starvation.
Fortress Nessus (p.75) - Mortals who spend time in this place must succeed at a DC 40 Fortitude save or take 1d6 wisdom damage, 1d4 Intelligence damage and 1d6 Charisma damage. This damage heals of its own accord 12 hours after leaving the layer.
Tabjari (p.75) - Magical Location worth 10,000gp, grants really powerful anti-Chaos abilities, but the prerequisites might not be easily achievable by a lesser character.

Monster Manual V
Spoiler
Demiplane of Filth (p.165) - Your favourite holiday spot.

Wizards of the Coast's website
Spoiler
The Demiplane of Ectoplasm where not only can you find some exotic fruits which bestow free Power Points (enough to manifest 9th level powers), but also sports the Enhanced Psionics magic trait. Suggested by Darrin.

Perilous Gateways series is brilliant! Basically a compilation of interesting venues and mini-quests regarding... portals. Special mention to Portals in Time article.

Non-standard Cosmology:
Spoiler
Dweomerheart (PGtF p.151) - All spells cast on Dweomerheart are extended, enlarged, and empowered.
Fugue (PGtF p.152) - All spells are impeded.
Divine Realm of Shar (PGtF p.162) - Stacks Plane of Shadow traits + maximizes and extends all Enchantment, Illusion, and Necromancy spells, as well as spells with the Darkness descriptor that are cast with Shadow Weave Magic. Light spells are impeded here.
Dal Quor (ECS p. 94) - Highly morphic; Flowing time 10:1 rate; Illusion spells are extended.
Dolurrh (ECS p. 95) - Heavy Gravity; Timeless; All spells are impeded; Entrapping: at the end of each day, a visitor must make a Will save (DC 15 + number days spend in the plane), failure makes the visitor an incorporeal shade, trapped in the plane - can only be restored by wish or miracle.
Thelanis (ECS p. 99) - Arcane spells are empowered and extended. Flowing time is 1:7 rate, though, which might make it useless, and downright dangerous, if one is not well prepared (see Ritual of the Timeless Soul PGtE p.60).
Elemental Plane of Ranch Dressing (http://www.giantitp.com/comics/oots0802.html) - Sorry for this one, but we have a commitment to true planar journalism.

Earth Nodes
Spoiler
As established in Underdark (p.49) Earth Nodes are places of magical power which source is the elemental Earth. You know what else is made of elemental Earth? The Elemental Plane of Earth, berk! Logically, then, one could find any class of Earth Node (ranges from level 1 to 9 pre-Epic) in the bloody Elemental Plane of Earth. Here's how this works: with the Node Spellcasting feat, you can check Spellcraft against a DC of Node's class + Spell's level to get a bonus to you caster level equal to the Node's class. So, within the confines of a class 9 Node, you get +9 CL. You also get some minor bonus, like access to thematic spells, the ability to stash items, and you can use the Metanode Spell feat, which gets you free metamagic levels equal to the Node's class. So, well, +9 CL and 9 levels worth of free metamagic for 2 feats? Sign. Me. Up.

Planar Touchstones
Spoiler
Originally Posted by Darrin

Here's a list of interesting basic abilities:

Arthenmyr's Wrath: Gain acid resistance 5.
Blinding Tower: Gain darkvision 60', or increase existing darkvision +30'.
Ice Catacombs: Gain cold resistance 5.
Monastery of Zerth'Ad'lun: +1 dodge bonus vs. melee attacks, or +2 dodge bonus vs. full-round melee attack.
Catalogues of Enlightenment: Choose a cleric domain, gain the domain power (see below).
Oxyrhynchus: gain extra attack at -5 penalty with chosen weapon whenever opponent is flat-footed.
Pilgrim's Rest: +1 untyped bonus to AC while on the material plane.
Valley of Thunder: +1 untyped bonus to AC.
Fields of Autumn: +1 untyped bonus on ranged attack rolls.
Ashardalon's Tongue: +1 untyped bonus on unarmed melee attack rolls.
Densahl's Challenge: +1 untyped bonus on melee damage rolls.
Restyn's Last Stand: +1 untyped bonus on melee attack rolls.
Peak of Continuation: Gain hardness 1, stacks with DR.
Salt Statuary (Sandstorm): Gain Improved Heat Endurance feat (i.e., fire resistance 5).
Dusty Conclave (Sandstorm): Improve natural armor bonus by 1.
Blue Dragon's Graveyard (Sandstorm): gain electricity resistance 5.

Now, the Catalogues of Enlightenment offer quite a bit more via various domain abilities. Also, it's important to note that the Catalogues do not require this domain to be part of your deity's portfolio... in fact, they don't require you to worship a particular deity at all, so you can cherry-pick some of the best domains without worrying too much about divine retribution. Here's a list of those that might be interesting:

Baator (Spell Compendium, Planar Domain): see perfectly in darkness or deeper darkness
Bestial (BoVD): gain scent
Celerity (Spell Compendium): increase land speed +10'
Demonic (BoVD/FC1): +1 divine/profane bonus on attack and damage with unarmed strikes and natural weapons.
Destruction (Core): smite naughty 1/day
Dream (Spell Compendium): immune to fear
Elysium (Spell Compendium, Planar Domain): smite evil 1/day
Fate (Spell Compendium): gain uncanny dodge ability.
Hunger (Spell Compendium): gain a bite attack
Inquisition (Spell Compendium): +4 bonus on dispel checks
Luck (Core): reroll any roll 1/day
Magic (Core): activate spell-trigger and spell-completion items as 1st level wizard.
Orc (Spell Compendium): smite naughty 1/day
Storm (Spell Compendium): gain electricity resistance 5
War (Core): gain weapon proficiency and weapon focus feats (see below)

The War domain, of course, offers a particularly juicy two-for-one deal... weapon focus and martial/exotic weapon proficiency for the cost of only one feat. This is particularly useful if you chose a deity with a great favored weapon, but the deity never had the common decency to add the War domain to his portfolio. Or... even if you don't worship that deity, and are just looking for an easy way to pick up EWP: Spiked Chain... well, here you go. A list of WF/EWPs that can be obtained via Planar Touchstone:

Bastard Sword (Note: Kord explicitly says (e) for exotic, while Kelanen and Mayaheine specify (m) for martial proficiency. The FRCS deities don't specify martial or exotic.)
Finder Wyvernspur (Forgotten Realms Campaign Setting p. 234)
Helm (Forgotten Realms Campaign Setting p. 234)
Kelemvor (Forgotten Realms Campaign Setting p. 234)
Kord (Living Greyhawk Deities v2.0 p. 96)
Eilistraee (Forgotten Realms Campaign Setting p. 237, Drow)

Chakram
Shar (Forgotten Realms Campaign Setting p. 234)

Claw Bracer
Luthic (Faiths & Pantheons p. 150)
Malar (Forgotten Realms Campaign Setting p. 234)
Sharess (Forgotten Realms Campaign Setting p. 234)
Urdlen (Faiths & Pantheons p. 137, Gnome)

Double Scimitar
Spirits of the Past (Faiths of Eberron p. 142)

Drow Scorpion Chain
Vulkoor (Secrets of Xendrik p. 72)

Dwarven Waraxe
Gendwar Argrim (Living Greyhawk Deities v2.0 p. 65, Dwarf)

Kama
Tem-Et-Nu (Sandstorm p. 45)
The Dark Six (Faiths of Eberron p. 49)
The Mockery (Faiths of Eberron p. 51)

Khopesh
Horus-Re (Forgotten Realms Campaign Setting p. 237)
Ramman (Lost Empires of Faerun p. 41)
Re-Horakhty (Sandstorm p. 47)

Net
Eldath (Faiths & Pantheons p. 222)
Istus (Living Greyhawk Deities v2.0 p. 84)
Marduk (Sandstorm p. 47)
Sotillion (Living Greyhawk Deities v2.0 p. 156)

Nunchaku
Waukeeen (Forgotten Realms Campaign Setting p. 234)

Pincer Staff (MM p. 164)
Blibdoolpoolp (Complete Divine p. 124, Kuo-Toa)

Scourge
Beshaba (Forgotten Realms Campaign Setting p. 234)
Loviatar (Forgotten Realms Campaign Setting p. 234)

Shuriken
Lliira (Forgotten Realms Campaign Setting p. 234)
Mystra (Forgotten Realms Campaign Setting p. 234)
Tymora (Forgotten Realms Campaign Setting p. 234)

Spiked Chain
Kossuth (Forgotten Realms Campaign Setting p. 234)
Tsolorandril (Living Greyhawk Deities v2.0 p. 171)
Zoser (Sandstorm p. 45)

Tail Scythe
Parrafaire (Serpent Kingdoms p. 188)
Shekinester (Seprent Kingdoms p. 188)

Whip
Al-Ishtus (Sandstorm p. 45)
Azul (Sandstorm p. 45)
Khurgobaeyag (Living Greyhawk Deities v2.0 p. 94, Goblin)
Lolth (Drow of the Underdark p. 19, Drow)
Myrhiss (Living Greyhawk Deities v2.0 p. 122)
Nepthys (Forgotten Realms Campaign Setting p. 237)
Pyremius (Living Greyhawk Deities v2.0 p. 137)
Sharindlar (Faiths & Pantheons p. 122, Dwarf)
Sune (Forgotten Realms Campaign Setting p. 234)

VIII. On offensive casting

So far, I have only proposed non-specific tactics with the tools at your disposal. Fret not, even if you have the creativity potential of an eunuch in an orgy, we will help you out:

Spells:
Spoiler
Anticipate Teleportation (Sor/Wiz 3) SpC - If you are teleporting your enemies around the battlefield, you might as well be casting Anticipate Teleportation every morning on yourself (and your familiar). This one grants you a round of leverage on anyone subject to teleportation effects. It also warns you of the exact location the target will arrive - better start laying those Battlefield Control spells around.
Anticipate Teleportation, Greater (Sor/Wiz 6) SpC - See above; preparation time before enemies pop back in escalates to 3 rounds.

Planar Bubble (Clr/Wiz 7) SpC - Its imperial majesty creates a 10ft. radius bubble around its target that "creates an area around the target creature that emulates its native planar environment". Now, we have been debating interesting planar spots for the best part of this handbook and you sure as hell have some ideas by now.
You can escalate the fun by carrying with you some objects crafted in various planar locations of interest and, at your convenience, cast Animate Object (or have a Ravid do it for you) and slap a Planar Bubble on top of them. You could even have some cheap Intelligent Ioun Stones (as intelligent magic items are considered creatures by themselves) floating around your head broadcasting your Planar Bubble of choice. Remember, the base spell is an emanation that you can block with total cover. Now, toss in some Sculpt Spell to change the "area: 10ft. radius emanation from touched creature" into whatever this feat allows (surprise, none of the allowed areas are emanations), and watch the fun begin. See, for instance, what Anthrowhale suggests as an interesting interaction between these concepts:

Originally Posted by Anthrowhale
You might want to discuss the use of 'static'. It sounds like an Initiate of Mystra with Vestments of Steadfast Spellcasting could precast a Planar Bubble to enter a static dead magic limited magic[all] timeless[magic] plane to setup a contingent resurrection/simulacrum/intelligent item that is native to the plane. At that point, casting Planar Bubble on the native makes it and possessed objects nigh-invulnerable on any plane they should visit while layering on desired additional permanent spell effects including offensive auras or retributions.
Plane Shift (Clr 5, Wiz/Sor 7) PHB - It is alright for Clerics, as a save or suck. Frankly, inferior to SoD spells (unless your target sports immunity to death/petrification/etc). If your foe is capable of planar travel, then this becomes meh as an offensive tool.
Greater Plane Shift (Clr 7, Wiz/Sor 8) Planar Handbook - Pretty much everything from its younger brother apply. Greater Plane Shift, however, takes your targets precisely to where you intend, as such, it merits a bump in power assessment as this bad boy rewards creativity.
Portal View (Portal 3, Brd 4, Sor/Wiz 4) Und - Makes a portal transparent; divination effect, not negated by True Seeing. Now, you might not think much of this, but say you pop a portal to whatever nasty place and cast Portal View on top of it, you have a solid stationary CC. To make things spicier, if you previously had Dimensional Anchor set up for you or your party members, you can kite people into it even more effectively.
Shalantha's Delicate Disk (Sor/Wiz 6) LEoF p.33 - Requires you to pre cast whatever spells you want into it, when broken - as a standard action - the spell immediately takes place. You can stack quite a truckload of those for your convenience.
Focal Stone (Sor/Wiz 5) online - Like gem magic, but it saves you a feat slot and some cash. Quite decent, actually.

Feats:
Spoiler

Inscribe Rune (PGtF p.40) It does require you to be divine caster, which is not exactly a hindrance. You may cast your spell with days in advance and store it in a rune, which can then be activate as a standard (or free) action. Bypasses long casting times.
Attune Gem (MoF p.21) Inscribe Rune, but flashier, more expensive and less abusable.
Earthbound Spell (PHBII p.91) - If you go for the time-bending aspect of this concept, via Anticipate Teleportation and juggling your enemies around with teleportation effects, suddenly this otherwise craptastic feat becomes somewhat interesting. It turns any non-personal spell into a 5ft. square trap. So, when your target finally arrives back at the battlefield, it'll be directly and immediately affected by whatever spell you stored. Spell level +2.
Melodic Casting (Complete Mage p.44) opens up an interesting option for you - you may cast a spell and activate a bardic music shenanigan as a rider effect. Now, flip your Champions of Ruin to page 20. See that Doomspeak thing there? If the target fails a Will save DC 10 + character level + Cha modifier) it takes -10 on attack rolls, saves, ability checks, and skill checks for a round. This is not a mind-affecting ability. Go crazy.

Class features:
Spoiler
A spellcaster's [Improved] Familiar or Symbionts (Fiend Folio, Eberron Campaign Setting, Magic of Eberron) can be made Outsiders and through Share Spells special quality can exponentially increase planar silliness - stack a few Planar Bubbles (keyed to different planes) atop each other (Hats off to LordofProcrastination and his Nasty Gentlemen).

If you dislike symbiont's fluff - and having to pay their feat tax to bind Naberius or to shape the Strongheart Vest - you can have your Improved Familiar become a Mirror Mephit (Expedition to the Demonweb Pits p.208). These guys have Simulacrum (CL 8) 1/day as a spell-like ability, which can target themselves. Which should be enough to warrant you a host of spell-sharing flying mirror thingies. Who said disco is dead?

Prestige Classes:
Spoiler
Archmage (DMG p.178) - Turning your spells into spell-like abilities, make them eligible for Supernatural Transformation (SS p.39), which means no components, and 1 standard action activation time for your precious 10-minute casting time spells.
Arcane Archer (DMG p.176) - 2nd level ability might allow you to bypass casting time for your Planar Breaching et al. If your DM lets you ignore racial requirements, as in playing a race that is not an elf, then this becomes blue
Anima Mage (ToM p.50) - Once per day cast any spell as an immediate action. Plus free metamagic shenanigans. Load up on Twin Spell and Planar Breach away.
Ordained Champion (CC p.90) - A solid class all in all. Channel spell ability lets you pre cast any spell into your weapon. Downside being even if it is an area spell, it will only affect the target of your attack.
Candle Caster (T&B p.53) - Haha, yes! Takes one round to light a candle that holds a spell. Exotic innit?

Items:
Spoiler
Glyph Seal, Greater (MiC p.161) - For meager 4,000gp you can store any spell of 5th or higher level and activate it by simply pressing the seal - which could be from a standard to a free action, depending on your rules lawyering.
Chardalyn (Silver Marches WE p. 3) - Spell-storing mundane material, so, hopefully you can produce a few through magic. Watch out for the costs, if you can't.

One staple trick of a space-folder is the liberal usage of the highest form of cover: Planes. It is stablished that you can Transdimensional Spell your heart's content from extradimensional spaces into the Material Plane. If you are in the Ethereal Plane, however, we have a couple more funsies:

Items:
Spoiler
Ethereal Reaver (Complete Psionic p.106) 40,000gp – The wielder may attack people on the Material Plane from the Ethereal Plane.
Tabard of the Disembodied (MIC) 68,600gp - The wearer may cast spells from the Ethereal into the Material plane
Ring of Free Magic (Planar Handbook p.80) 45,000gp - Allows its wearer to ignore the effects of the Limited Magic planar trait for a few charges. Might be quite useful on an emergency or if you choose to pick Limited Magic (all schools) within an offensive-oriented Planar Bubble so to thrash an overconfident Initiate of Mystra.

3. ## Planewalking – a guide for bending time and space

IX. Moving around

A selection of non-obvious effects that allow you to go from planar point A to planar point B sans the usage of portals, listed mostly for curiosity and fun.

Items:
Spoiler
Psigate (Complete Psionic p.117) 2,500gp - A psionic character able to expend 9 power points can manifest Psionic Planar Shift as a psi-like ability once for the next 24 hours. Quite cheap investment for plane hopping ability. If you are not a psionic character, fret not: look up section VI. under Wizards of the Coast's website for the Demiplane of Ectoplasm.
Rope of Crossing (PlH) 90,000gp - Allows planar travel across the layers of an Outer Plane. Not spectacularly useful, but I find the concept of crossing planar borders through climbing up or down a rope amusing.
Figurine of Wondrous Power: Obsidian Steed (DMG) 28,500gp - A black stalion that can plane shift and ethereal jaunt at will for 24 hours a week? I'll have mine with fries.
Amulet of the Planes (DMG) 120,000gp - Expensive, yes, but it explicitly states that it gets you to "the plane (and the specific location on that plane) that [you want]".
Tapestry of Travel here 16,200gp - A rather amusing concept for an item: once a day it teleports the activator and a couple of mates to the place depicted in the tapestry. Stylish, to say the least (suggested by Bronk).
Planar Sails (A&EG, p. 50) 72,000gp - 5 minutes and a DC 20 Knowledge: planes check make up for one of the coolest plane-traveling concepts around (suggested by Bronk).

Creatures:
Spoiler

Nightmare (SRD or MM p.194) we have all heard about someone who got his character sheet burnt to ashes for abusing Astral Projection.
Ur'Epona (PlH p.131) can plane shift 1/day. They are 3 HD Magical Beasts which may be trained by a Handle Animal DC 25 Check. Arguably the cheapest plane shifting trick accessible, albeit a tad GM-dependent. Arms & Equipment Guide brings some pricing for monstrous mounts; extrapolating from the Owlbear, for example (a 5 HD magical beast), at 3,000gp, an Ur'Epona (a 3 HD Magical Beast) might be sitting around 1,750gp. Alternatively, Lords of Madness p. 101 brings up rules for slavery. The value of slaves is a different matter. Multiple factors go into the value of a slave, and the interest shown by the potential buyer is not the least. The basic method for determining the value of a slave is based on the creature’s CR, using the following formula:
Cost = (CR, minimum 1)2 × 100 gp
An unskilled dwarf, for example, with CR 1/2, costs 100 gp (CR 1/2 rounds up to 1; 1 squared = 1; 1 time 100 gp = 100 gp). A troll slave, on the other hand, costs 2,500 gp (CR 5 squared = 25, times 100 gp = 2,500 gp).
Elsewhale (PlH p. 117) C'mon, when was it the last time you could pull a Jonah on your wife and tell her you came home late because a whale swallowed you and then planeshifted to a casino?

Affiliations:
Spoiler
Fharlanghn's Way (Complete Champion p.14) - Church affiliation; nice fit, as the theme goes. At max rank you can become ethereal once per day. If you push it hard enough, you can get it as an extraordinary ability past a lenient DM. Not counting on it, but, well, still a nice extra anyhow.

X. Utility and miscellany

Spells:
Spoiler
Portal Beacon (Clr 1, Sor/Wiz 1) SpC - Allows your party to GPS-track you if you pop open a portal and cast this upon it.

Items:
Spoiler
Fiendring (LEoF p.152) 30,000gp - As the Fiendform spell, the wearer assumes the form and all abilities of any fiendish creature, demon, or devil from Summon Monster I through IV lists - and, most importantly, the outsider type. One activation per day which lasts 12 minutes. Quite useful for Planar Bubbling.
Ring Gates (DMG) 40,000gp - Creates a portal-like link up to 100 miles. Spells can be cast through the gates.
Ring Gates, Planar (PlH) 200,000gp - Much more useful for the purposes of this guide, albeit excessively expensive, but creative Planewalkers and their allies - or familiars - should be able to put these rings to great effects.
Vestments of Steadfast Spellcasting (PlH) 25,000gp - Wearer may ignore magic traits (except for dead magic) of a plane. Quite the boost in limited or impeded magic places.
Skin of the Celestial (Complete Psionic p.109) 10,000gp - Gains the celestial template for 7 consecutive rounds per day.
Skin of the Celestial Embrace (Complete Psionic p.110) 48,000gp - Gains the half-celestial template for 15 consecutive rounds per day. Since we're using this for Planar Bubbles purpose most likely, this is quite the expensive investment.
Skin of the Fiend (Complete Psionic p.110) 10,000gp - Gains the fiendish template for 7 consecutive rounds per day.
Skin of the Fiendish Embrace (Complete Psionic p.110) 48,000gp - Gains the half-fiend template for 15 consecutive rounds per day. Since we're using this for Planar Bubbles purpose most likely, this is quite the expensive investment.

Incantations:
Spoiler
Call Forth the Dweller (UA p.176 or here) - Summons an eldritch horror to answer questions about doors (or other such things, like portals for instance). It can give you hints about what is beyond, the key, who made it, etc. It is pretty useful in adventures where the travelling is done through external, to the characters, means. Suggested by Feantar.
Hrothgar's Journey (UA p.177 or here) - Which, well, burns down your house and takes you (and your party) to Ysgard. Which is kinda situational, but it's planar travel nonetheless.

Feats:
Spoiler
Naturalized Denizen (Unearthed Arcana p.94) You are never treated as having the extraplanar subtype - so you are immune to banishing effects. Might be worth considering in a planar campaign, otherwise, still a nice fluff feat.
Sanctum Spell (Complete Arcane p.82) Well, here’s an opportunity for using the feat as intended by the game designers. Of course, you could always use it to circumvent hard limits from spells such as Invoke Magic, Arcane Fusion, and the likes.
Planar Tracker (Dragon 306, p.55) Allows you to track your quarry even after it teleports or plane-shifts (suggested by Bronk).

Monsters:
Spoiler
Dharculus (PlH p. 112) 8HD Aberration that has the "Dualplanar" Extraordinary quality, allowing it to extend an appendage from the Ethereal plane into the Material plane as a standard action.

Rituals:
Spoiler
Ritual of the Timeless Soul (Player's Guide to Eberron p.60) Tucked away in this not-so-popular splatbook lies this precious gem: it is not a feat or a spell, rather a ritual. What's so good about it? It makes you immune to any *harmful* effects of flowing time due to planar travel. I'll have two for the road, thank you.

Places:
Spoiler
Failed Shadow Gate (Cormyr p.154) 5,000gp - A Magical Location that grants the ability to assume the Dark template for up to 10 minutes/day - after 10 successful activations of the Magical Location, you get the template permanently. Nice for Planar Bubbling illusions.

Alternate Class features:
Spoiler
Shadow Sword Ranger (CoV p.49) - Coming online at ranger level 8, it could see lots of use in planar campaigns for your planewalker's companions. The ability itself is quite decent, automatically detecting portals within 10ft., and not only effectively making you able to analyze portal at will, but actually granting you a free portal well once a day. This is only being tagged red as it escapes all recommended chassis for a planewalker: ranger 8 is not exactly splash friendly for caster-heavy builds (suggested by Dalmosh).

Erm… stuff:
Spoiler
Planar Motes (Complete Scoundrel p.119) - Sort of plant creatures that can be stored within jars. Alignment-detecting effects register the motes' alignment instead of their holder. Good for sneaking around hostile planes.

XI. Avoiding AMF/dead magic zones and planes

Now, when facing magic-denying enemies, the usual response is Initiate of Mystra or minionmancy. We will do no such thing. Flip your DMG to pages 147, 148, and 149: Extradimensional spaces have normal gravity, time, and magic traits. Smiling yet? You should!
If you're ever caught with your pants down, toss in Invoke Magic (Sor/Wiz 9) LoM followed by a Sanctum Arcane Fusion: Shadow Well + Sanctum Portal Well. This allows you to rain Transdimensional instantaneous Conjuration (Creation) spells on the other side with impunity. Consider adding Invisible Spell to Shadow Well for added hilarity.

Once on the other side, Planar Bubble and other effects that might tinker with the battlefield’s Magic Traits might stabilize the region for you and your friends to rain death upon your foes. You heard it. “Death” – Theoden, King.
In case your DM rules out metamagic spells within Arcane Fusion just vanilla Invoke Magic + Shadow Well and have either a Contingent Portal Well or have your familiar peck at a Glyph Seal (MIC pg.161) with a stored Portal Well.

Thought we only had this one trick? Haaaave you met:
Ether Scarab (MMII, pg. 94)? It can rip a portal through planes that lasts for 1d4+1 rounds as (Su). As an Extraordinary ability, however, its death throes create a two-way portal to the ethereal for 1d4+1 rounds; arguably, a few Ether Scarabs could be held frozen in Temporal Stasis (Sor/Wiz 8) or Quintessence (EXP), ready to be squashed in an emergency.
From there you can Melodic Cast Transdimensional Spells at the same time you divert the open portal back to the material plane.
As a last note on this section, although not quite antimagic, but effects that prevent planar travel can ruin your day. But, for meagre 11,200gp, the wearer of a pair of Bracers of Exit (A&EG) may ignore Dimensional Anchor 1/day.

XII. Persistent Extradimensional and/or Prison-like effects

For when you need to actually keep things alive and locked away.

Items able to store living creatures:

Spoiler

Mirror of Life Trapping (DMG) 200,000gp - Holds up to 15 creatures as prisoners; their equipment is left behind. You heard right: Free loot.
Rod of Security (DMG) 61,000gp - Holds up to 200 creatures divided by 200 days (i.e.: 1 creature for 200 days or 200 creatures for 1 day each).
Stasis Sphere (Silver Marches) 137,700gp - Holds up to 50 creatures of any size; May be breached - 20 hardness, 50 hit points.
Husk of Infinite Worlds (Magic of Eberron p.123) It is presented as an "artefact-level item" rather than a major or minor artefact. Regardless, one would not like to be trapped within one of these, though it might not exactly fit the ‘alive’ clause for long.
Bag of Devouring (DMG) 3.0 DMG had it listed for 15,500gp; 3.5 upgraded it to an artefact. Actually, this cursed magic item is a living creature. 50% chance that creatures thus devoured will be gone forever.
Bag of Holding I (DMG) 2,500gp - 30cu ft. or 250lb.
Bag of Holding II (DMG) 5,000gp - 70cu ft. or 500lb.
Bag of Holding II (DMG) 7,400gp - 150cu ft. or 1.000lb.
Bag of Holding IV (DMG) 10,000gp - 200cu ft. or 1.500lb.
Enveloping Pit (MIC) 3,600gp - 10ft. wide 50ft. deep
Handy Haversack (DMG) 2,000gp - 8cu ft. or 80lb.; two additional spaces of 2cu ft. or 20lb. each
Hole of Hiding (Strongholder's) 3,000gp - permanent rope trick; wondrous architecture
Nondimensional Trunk (A&EG) 30,000gp - 10cu ft. or 200lb.
Portable Hole (DMG) 20,000gp - 6ft. wide 10ft. deep; enough air for 1 medium or 2 small creatures
Saddlebags of Holding (A&EG) 5,000gp - 30cu ft. or 250lb.
Saddlebags of Providing (A&EG) 8,000gp - 10cu ft.; additionally, enough food for its wearer for a day, every day
Smuggler's Hold (A&EG) 90,000gp - 10cu ft. or 200lb.; divinations must succeed a CL check DC 20 to locate it

Items able to store non-living matter only:
Spoiler
Battle Cloak of Vycaena (LEoF) 38,000gp - Two 20lb. spaces; +4 armour bonus, +1 saves; may retrieve items as a free action
Belt of Hidden Pouches (MIC) 5,000gp - 10 small spaces of 1/2cu ft. or 5lb.
Belt of many pockets (CAr) 11,000gp - 1cu ft. or 10lb.; alternatively, the caster's familiar, no matter its size
Casting glove (DMGII) 25,000gp - 20lb.; stores or retrieves items as a free action; may use stored items as a standard action
Duo-dimensional Jug (City) 1,000gp - Stores a gallon of liquid
Glove of Storing (DMG) 2,200gp - 20lb.
Gloves of the master strategist (Ghost) 3,600gp - 20lb.; True Strike 1/day
Infinite scrollcase (MIC) 2,800gp - Stores up to 50 scrolls; may draw scrolls as part of a move action
Ring of arming (MIC) 2,500gp - Stores or reequips weapons and armours upon activation
Najjar's Cloak of weaponry (PGtF) 2,500gp - 25lb.
Zundaerazylym's Nevertokens (CoV) 67,000gp - 20lb.; doubles as a ring of feather falling and ring of mind shielding; 1/day - sending, teleport, and know direction

XIII. Hipster Prestige Classes that add uh... something

Goddamend millennials are gentrifying everything these days.

Spoiler
Gatecrasher (Manual of the Planes p.26) - At level 3, a Gatecrasher can use the Open Lock skill to open gates and portals, even if they are sealed. Even portals created or locked by deities can be opened, albeit at a DC of 50. Not game breaking, but... well, never mind, this can totally wreck a campaign.
Planar Champion (Manual of the Planes p.28) - 7th level ability Rip Portal tears the multiverse a new one, in the form of a rift between anywhere and the Astral Plane, or any other plane touched by the Astral. Provided you are in a place where you can actually access the Astral Plane.
Planeshifter (Manual of the Planes p.31) - Now, this one is actually semi-useful and the fluff clicks. Sadly, it misses out 3 casting levels and the good abilities come at level 9 and 10, respectively the ability to swap a 100-foot-radius per class level sphere from one plane to another and to create a demiplane - unfortunately this last one, unlike Genesis, does not allow you to set the time and magic traits of your personal plane.
Astral Dancer (Planar Handbook p.63) No-gravity environments allows you minor defensive abilities.
Goldeneye (Faiths & Pantheons pg.194) - Personal extradimensional space at level 5; +1 spellcasting every level.
Hoardstealerr (Draconomicon, pg.130) - Personal extradimensional space at level 3; mediocre spell list.
Silver Key (Dragonmarked, pg.120) - Bypass glyphs and breaks into extradimensional or planar portals at level 10. Really cool ability, on an otherwise sort of useless skill-monkeyish class.
Horizon Walker (Dungeon Master's Guide p.189) From 6th level and onward, Planar Terrain Mastery might grant you a few tricks. Special note to "Shifting (Planar)" which allows you to use Dimension Door every 1d4 rounds.
Alienist (Complete Arcane p.21) At 10th level you gain the Pseudonatural template. Just… don’t.
Wayfarer Guide (Complete Arcane p.65) - At first level, Improved Range boosts your [teleportation] spells' range by 50%.
Wild Mage (Complete Arcane p.69) - As per side bar, whenever you are under the effects of a wild magic zone, you may roll twice and pick whatever result you want. Pairs nicely if you want to flood the world with wild magic planar bubbles or manifest zones.
Anarchic Initiate (Complete Psionic p.18) - At 6th level the Initiate can cause a Minor Breach to bleed into Limbo, at 10th level, it becomes a Complete Breach. Guess this is fine if you’re a manifesting character. The adaptation section can yield some fun variants.
Planar Vanguard (http://archive.wizards.com/default.a.../psm/20031219a) This one looks like it was written for me. Too bad it is psionic-centric, but I am sure some of you will grow to love this class. It has everything: from the ability to ignore some negative planar traits to create a Reality Maelstrom. With some luck (and a few bribes) one might be able to adapt this to a regular spellcasting class. Would be the best topping a Bard/Sublime Chord could have for the planewalker concept.
Jaunter (Expedition to the Demonweb Pits p.172) - This one is rather fun, as it allows mundanes to tinker with Anticipate Teleport shenanigans. Suggested by ShurikVch.
Lord of the Tides (Sandstorm p.70) - Not where you'd expect to find something planar-related. Well, this bad boy packs 9/10 spellcasting progression, a humble Burrow speed, but, mate, will you like the capstone, oh boy. Twice a day you can create a two-way portal to a location you have visited in any Inner Plane. Now, this is good enough as it is, but have you tried pairing it with Earth Nodes? - let us show some hands for Thedez for suggesting this one.
Divine Agent (MotP p.24) - 5/10 caster progression; capstone, however, is a (Sp) Gate usable 1/day to your patron's plane. Not bad if you can pair with a fast-progression casting class. Suggested by ShurikVch.
Hellbreaker (FC II p.86) - This is a rather interesting class for a rogueish character. You carry a disruption field that hinders telepathy, summoning, and calling effects; can hitch a hike with any [teleportation] effect cast in the immediate vicinity; can steal (Sp) and (Su) abilities; and, best of all, immediate action Plane Shift. You even get some sneak attack dice. Would definitely be bumped into gold if it progressed any spellcasting at all. Special Thanks to ShurikVch for bringing this beauty to my attention.
Singer of Concordance (RotD p.91) - Interesting concept overall, capstone gives you a non-customizable demiplane to which you can retreat (with your buddies in your arms) at will. Also sports some dimensional anchoring shenanigans. Thanks to ShurikVch for his contribution.

XIV. Power! Unlimited Power!

If you opt for the Bard 6 chassis, which I strongly advise you to do, and find yourself in a high-powered game, you have a few interesting options to join the demolition crew:
The sane approach is to book a few trips to Heward's Hall (Complete Scoundrel p.146) and stack copies of Extra Music for 5,000gp each. It might be that your DM rules that Extra Music is not a Bardic Music feat, but rather a General feat - I would beg to differ, as the most recent print of Extra Music is in Eberron Campaign Setting p.52 and, even though it carries the General tag, so do all other obviously bardic music feats in that book. A similar thing occurs in Complete Adventurer, where all bardic music dependent feats all lack a "bardic music" tag. Appeal to reason.

The absolutely bonkers move, however - and refrain from pursuing it unless you're in a Marvel Universe-esque campaign - involves the 8HD Firre Eladrin (Book of Exalted Deeds p.169):
Spoiler
Song (Su): A firre has a captivating voice and can use bardic music just as a bard can, inspiring courage, fascinating, inspiring competence, or giving suggestions to those who hear it Unlike a bard, however, a firre can sing as often as it likes.

So, Channel one (Book of Exalted Deeds p.23) - you can accomplish it via castings of Planar Ally/Planar Binding (PHB) or the Channel Celestial (Sanctified 7) spells. Alternatively, you can Polymorph + Assume Supernatural Ability, provided you are an Outsider, or simply Shapechange. In anything-goes-campaigns, you could even consider Savage Species rituals (especially the one on p.150) to irrevocably turn yourself into a Firre Eladrin.
Couple this with the Lyric Spell feat (Complete Adventurer p.113) and/or Metamagic Song (Races of Stone p.142) - which respectively trade bardic song usages for spell slots, and metamagic application. Voilà: infinite free-metamagic spells. Toss in Arcane Disciple: Luck for good measure and wreck your campaign with infinite Miracles.

XV. Sample builds

i. Bard 6, Divine Prankster 5, Sublime Chord 2, Incantatrix 7
This one does everything: Planar Bard substitution for maximum autonomy, Sublime Chord for level 9 spells, Incantatrix for metamagic goodness and Divine Prankster (qualified via Planar Touchstone) for enraging people into following you through portals. Usual combat should look like this: round 1 – Melodic Cast a portal-opening effect with an Enrage Enemy (Divine Prankster 5) rider effect, then 5ft step into the portal behind you plus Quickened Portal Well. Enemy will follow you and end up in whatever nasty place you targeted the portal to in the first place.
Variants: drop Divine Prankster and go creative. I am personally fond of using Planar Touchstone: Catalogues of Enlightenment for Divine Prankster’s qualification, so, if you’re keeping it, might as well go for Dweomerkeeper instead of Incantatrix, which is arguably more powerful, since you can get 10-minute long casting times reduced to 1 standard action through DK's Supernatural Spell.

ii. Rogue 1, Bard 6, Chameleon 10, Gatecrasher 3
The quintessential Gatecrasher, as described by the Manual of the Planes. Sadly, you miss out on the higher-level spells, unless you get yourself into some shenanigans (Sanctum Spell/Earth Spell/Improved Sigil: Krau + Extra Spell or other usual methods). Even if you are left in the dust, bereft of Planar Bubble and the likes, you can do some serious wrecking with Gatecrasher’s 3rd level ability. Do not go for it unless your DM is highly capable of improv and has gone through proper anger management therapy.

iii. Bard 8, Spelldancer 2, Lyric Thaumaturge 10
Even if you load up on Portal Dissonance, you do not want to miss out on those Sor/Wiz spells, like Perinarch, Shadow Well, or Precipitate Breach. Lyric Thaumaturge solves that for you. Too bad spellcasting caps at 6th level, but this is supposed to allow other spellcasters to shine. Spelldancer added for good measure, as you most definitely can use some Chain, Repeat, or Persist Spell.
Variants: Recaster or, if you grab the Arcane Preparation feat, Wyrm Wizard can replace Lyric Thaumaturge nicely. Other sources of spell knowledge do exist, but they’re not as nice as these two.

iv. Bard 6, Lord of the Tides 1, Gatecrasher 3, Sublime Chord 1, Lord of the Tides 9
This one lacks metamagic shenanigans, but, as noted by Thedez, Lord of the Tides' capstone allows you to craft mobile portals that you can pop open twice a day. Gatecrasher's 3rd level ability lets you crack open closed portals - even if they were sealed by deities. Bard 6 thrown in for good measure and some Sublime Chord on the side for your 9th level spells.

Non-bard-centric builds should ideally acquire an Orrery of the Planes or a Passage weapon (see Section II. On Creating Portal Surfaces) on top of which you would stack the rest of your planar bending skills. Barred those, not only until you acquire 6th level spells, such as Portal-to-Portal Redirect, will you ever have absolute control over what traits and destinations you will be dealing with. 7th level spells open Planar Bubble + Planar Chasuble combo, however, which should make you not feel bad for not having those Bard levels.
Probably the early stages of your career will be centred around teleporting people and setting up CC via Anticipate Teleportation – while still in the spirit of bending time and space, it still is not the main course of this dinner. That being said:

v. Druid 10/Planar Shepherd 10
I feel like I should not need to explain this one.
Variant: Where I do feel the need to explain it but am too lazy to do so.

vi. Archivist or Wizard 20
See Druid 10/Planar Shepherd.

XVI. Final Words

No Doctor Who fans were hurt in the production of this handbook.

4. ## Re: Planewalking – a guide for bending time and space

Do you have the portal variant listed from IIRC the Underdark book that let's you use the Create Portal feat to make portals that allow for noncreature materials to flow tgrough?

Second, have you made note of the text in Manual of the Planes that again IIRC says portable extradimensional spaces are treated as their own demiplanes?

(apologies if the above rambles, am mildly medicated after a tooth removal. am asking because I was having trouble checking for these bits of info in your text. thanks for your patience.)

EDIT
FYI Dead magic zones inherit from the Antimagic Field spell. Again this too got cooypasta'ed from the MotP to Planar Handbook.

5. ## Re: Planewalking – a guide for bending time and space

Didn't see the Telflammar Shadowlord or the Crinti Shadow Marauder. Might be a nice addition here due to their Shadow Pounce. The Sha'ir gets its spells from the elemental planes so it might also be good to add it.

6. ## Re: Planewalking – a guide for bending time and space

Do you have the portal variant listed from IIRC the Underdark book that let's you use the Create Portal feat to make portals that allow for noncreature materials to flow tgrough?
Hm, very nice catch!

Second, have you made note of the text in Manual of the Planes that again IIRC says portable extradimensional spaces are treated as their own demiplanes?
Yessir, it is, in fact, the chassis of the antimagic circumvention trick, down in section X, as vanilla demiplanes have standard traits in regards to everything.

Didn't see the Telflammar Shadowlord or the Crinti Shadow Marauder. Might be a nice addition here due to their Shadow Pounce. The Sha'ir gets its spells from the elemental planes so it might also be good to add it.
They do, indeed, involve planar shenanigans, but escape the concept proposed in the handbook, as shadow pouncing/walking merely takes you from point A to B, sans the whole 'portal' thing, which is what I'm actually seeking to weaponize.

7. ## Re: Planewalking – a guide for bending time and space

One of the Dragon magazines has a decent write up of the Plane of Radiance, IIRC it's the opposite of the Plane of Shadow.

8. ## Re: Planewalking – a guide for bending time and space

Originally Posted by unseenmage
One of the Dragon magazines has a decent write up of the Plane of Radiance….
The future’s so bright I gotta wear shades?

This is Dragon #321, an issue heavy on the planes and Forgotten Realms deities.

9. ## Re: Planewalking – a guide for bending time and space

The Shadowsword Ranger variant from Champions of Valor has some quite useful planewalking abilities, I used one in my last campaign as the closest thing I could find in 3.5 to emulate Roland Deschaine for a new player.

Um... I'd personally love to see Psionics included in this if you did feel like extending it this way. Be interesting to look at the numbers of what Nomads are capable of doing better than arcane mages. Psionics seems to be the go-to for Chronomancy shenanigans for a start.

10. ## Re: Planewalking – a guide for bending time and space

Regarding Portal Dissonance: how farfetched would it be to use it as a cheap mean of teleportation to and from cities, fortresses, PC bases, dungeons, and whatnot? After all, what's a doorway, a gate, or other large door-like structure used to enter or navigate through a structure if not a nonmagical intraplanar portal with two adjacent rooms (or a room and the outside world) as natural endpoints?
This would make planar bards quite valuable, both as guides or escorts (since you can now easily move back to town to restock supplies and sell loots and then return to the dungeon) and as spies, assassins, or generals (as stepping inside an enemy fortress in the last 30 days means you can teleport yourself and your allies there easily).

As for using Portal Well offensively by hiding inside it and then cast Transdimensional Spells at your enemies, it doesn't work:
Originally Posted by Transdimensional Spell
A transdimensional spell has full, normal effect upon incorporeal creatures, creatures on the Ethereal Plane or Plane of Shadow, and creatures within an extradimensional space in the spell's area. Such creatures include ethereal creatures, creatures that are blinking or shadow walking, manifested ghosts, and creatures within the extradimensional space of a rope trick or portable hole. You must be able to perceive a creature to target it with a spell, but you do not need to perceive a creature to catch it in the area of a burst, cone, emanation, or spread. A transdimensional spell uses up a spell slot one level higher than the spell's actual level.
Which means an opponent could cast a transdimensional fireball to hit you while you're inside a portal well, but you wouldn't be able to do the opposite (because you are targeting a creature outside an extradimensional space). It's also worth noticing that you can't actually target a creature outside an extradimensional space you're in, because you don't have LoS/LoE to it.

11. ## Re: Planewalking – a guide for bending time and space

Originally Posted by Palanan
The future’s so bright I gotta wear shades?

This is Dragon #321, an issue heavy on the planes and Forgotten Realms deities.
Oh, I'll definitely be checking that issue. Thanks, folks!

Originally Posted by Dalmosh
The Shadowsword Ranger variant from Champions of Valor has some quite useful planewalking abilities, I used one in my last campaign as the closest thing I could find in 3.5 to emulate Roland Deschaine for a new player.

Um... I'd personally love to see Psionics included in this if you did feel like extending it this way. Be interesting to look at the numbers of what Nomads are capable of doing better than arcane mages. Psionics seems to be the go-to for Chronomancy shenanigans for a start.
The analyze portal bit fits the concept nicely, indeed. But I don't believe it could add much to the toolkit that a spell couldn't replicate. But, then, if you're building a whole party for planar adventures, it would certainly be an interesting addition.

As for the chronomancy bit, you are absolutely right: manifesters wipe the floor with spellcasters in regards to this theme. I should probably study the Expanded Psionic Handbook a bit.

Originally Posted by Uncle Pine
Regarding Portal Dissonance: how farfetched would it be to use it as a cheap mean of teleportation to and from cities, fortresses, PC bases, dungeons, and whatnot? After all, what's a doorway, a gate, or other large door-like structure used to enter or navigate through a structure if not a nonmagical intraplanar portal with two adjacent rooms (or a room and the outside world) as natural endpoints?
This would make planar bards quite valuable, both as guides or escorts (since you can now easily move back to town to restock supplies and sell loots and then return to the dungeon) and as spies, assassins, or generals (as stepping inside an enemy fortress in the last 30 days means you can teleport yourself and your allies there easily).

As for using Portal Well offensively by hiding inside it and then cast Transdimensional Spells at your enemies, it doesn't work:
That, sir, gave me an excellent idea.

As for the Portal Well bit, the intended use was to actually entrap people in extradimensional spells. The Portal Well was added as means of confusing eventual pursuers, but, then, I guess I got carried away. I will rectify that. Thanks for the heads-up!

12. ## Re: Planewalking – a guide for bending time and space

As a Planescape and planar lover and a friend of one who's sitting right beside me as I type this, my heart goes aflutter for your aid. Thankee!

13. ## Re: Planewalking – a guide for bending time and space

Love the guide, will look further.
Originally Posted by Uncle Pine
Regarding Portal Dissonance: how farfetched would it be to use it as a cheap mean of teleportation to and from cities, fortresses, PC bases, dungeons, and whatnot? After all, what's a doorway, a gate, or other large door-like structure used to enter or navigate through a structure if not a nonmagical intraplanar portal with two adjacent rooms (or a room and the outside world) as natural endpoints?
This would make planar bards quite valuable, both as guides or escorts (since you can now easily move back to town to restock supplies and sell loots and then return to the dungeon) and as spies, assassins, or generals (as stepping inside an enemy fortress in the last 30 days means you can teleport yourself and your allies there easily).
This seems very far-fetched, unless you have text supporting the reading that a common door is a "nonmagical intraplanar portal," and I'm not saying dictionary definitions. It seems to be the most pedantic reading of RAW ever, and something that should not be mentioned

14. ## Re: Planewalking – a guide for bending time and space

This is a great resource, thanks!

A few extra things for possible inclusion:

AEG also has the Planar Sails for 72,000 gold (plane shift an entire ship every ten minutes) and the Dimensional Prism (force beings from a transitive plane into the Prime Material for 1d6 rounds).

The enveloping pit is updated in MIC as 3600 gold, instead of 33600 gold.

Amethyst, Crystal, and Emerald gem dragons have the 'planar travel' ability, allowing them to pop between the Prime Material and the inner planes at will.

The prismatic ray/spray/wall spells could go on your magic lists.

Mirror of Mental Prowess (SRD, 175000 gold), creates a portal to a scryed location
Mirror of Translocation (Dragon 305, 153200 gold), come in a pair, teleports you to the other mirror even across planes
Amulet of Astral Projection (Dragon 306, 320320 gold), astral project with up to 8 passengers, but take int damage on return
Extradimensional Anchor (Dragon 306, 112000 gold), an item of dimensional anchor with a 40' radius
Dimensional Tracking Net (Dragon 308, 64320 gold), allows tracking across dimensions
Dimensional Pocket (Dragon 313, 9000 gold), basically an invisible sticky bag of holding
Corporeal Lodestone (Dragon 342, 39000 gold), prevents travel to and from the ethereal, and is bound to the Prime
Tapestry of Travel (Fey Feature, 16200 gold), teleport to the location depicted on the tapestry
http://archive.wizards.com/default.a.../fey/20030613a

Dragon 306 has the 'Planar Tracker' feat.
Dragon Compendium has the 'Astral Tracking' feat.

Dragon 287 has more takes on the dream realm.

15. ## Re: Planewalking – a guide for bending time and space

Originally Posted by JMS
Love the guide, will look further.

This seems very far-fetched, unless you have text supporting the reading that a common door is a "nonmagical intraplanar portal," and I'm not saying dictionary definitions. It seems to be the most pedantic reading of RAW ever, and something that should not be mentioned
The literal reading of any door frame as a D&D portal, it is indeed quite the stretch, but the tactical idea behind it is quite good: the Create Portal feat(FRCS pg.34) or the Create Crossroads and Backroad (Druid 7, MoF pg. 86) spell could make that work; even though both are a tad expensive, they should be worth it, under the circumstances Uncle Pine described: either as a standalone tool for an impromptu (albeit permanent) backdoor access into an enemy stronghold, or as a portal detour back to the party's HQ. A "save point" of sorts in both cases, as they would anchor the end of a portal, thus constituting valid targets for Portal Dissonance.

16. ## Re: Planewalking – a guide for bending time and space

Added suggestions from Dalmosh, Uncle Pine and Bronk. Thanks, folks, keep em coming!

17. ## Re: Planewalking – a guide for bending time and space

Not sure how guide worthy it is but one high wealth thing I've done is to string Planar Ring Gates throughout many extradimensional storage medium and use Crawling Claws (MoF) to fetch me things from them.
With a word just about anything small enough can be carried from my Portable Hole or private demiplane to my Handy Haversack instead where its but a move action away.

Also of note is redirecting teleports or planar coordinates to a time locked space via either lots of Quintessence or a demiplane with a static time trait.

Could also use the Stronghold Builders Guide Wondrous Architecture or Draconomicon Lair Wards with the Combining Magic Items rules in MIC to add planar portals to a room or the reverse.

Intelligent Magic Items and planar magics is neat too. If the GM interprets the line about them counting as creatures literally then they can have Contingent spells on them and, unless I'm missing something, their contingent Plane Shift or Teleport can still take other folk with them, including their wielder.

Alternatively, the line of text that says Int Magic Items can activate their own superpowers makes them interesting if installed in a planar portal especially if that portal is also enchanted with some portal redirection magics or similar magics.

Could even have the Int Magic Item be responsible for Greater Plane Shift or Greater Teleport ing subjects of its choosing (perhaps via quiz or riddle) while the actual portal only leads to a trapped destination or other unpleasantness.

EDIT Speaking of G. Plane Shift and G. Teleport... are they listed? My ctrl+f wasn't finding them.

18. ## Re: Planewalking – a guide for bending time and space

So Bard 6 with a passage sword is open to many shenanigans. Wow. I could just play that alone.

19. ## Re: Planewalking – a guide for bending time and space

Originally Posted by unseenmage
Not sure how guide worthy it is but one high wealth thing I've done is to string Planar Ring Gates throughout many extradimensional storage medium and use Crawling Claws (MoF) to fetch me things from them.
With a word just about anything small enough can be carried from my Portable Hole or private demiplane to my Handy Haversack instead where its but a move action away.

Also of note is redirecting teleports or planar coordinates to a time locked space via either lots of Quintessence or a demiplane with a static time trait.

Could also use the Stronghold Builders Guide Wondrous Architecture or Draconomicon Lair Wards with the Combining Magic Items rules in MIC to add planar portals to a room or the reverse.

Intelligent Magic Items and planar magics is neat too. If the GM interprets the line about them counting as creatures literally then they can have Contingent spells on them and, unless I'm missing something, their contingent Plane Shift or Teleport can still take other folk with them, including their wielder.

Alternatively, the line of text that says Int Magic Items can activate their own superpowers makes them interesting if installed in a planar portal especially if that portal is also enchanted with some portal redirection magics or similar magics.

Could even have the Int Magic Item be responsible for Greater Plane Shift or Greater Teleport ing subjects of its choosing (perhaps via quiz or riddle) while the actual portal only leads to a trapped destination or other unpleasantness.

EDIT Speaking of G. Plane Shift and G. Teleport... are they listed? My ctrl+f wasn't finding them.
Hm... I see some potential there. Especially the bit concerning Intelligent Items counting as creatures - if we could pop around all over the planes crafting intelligent items that can cast Planar Bubble a few times a day... you see where I'm going.

On the plane shift/teleport subject, I've renamed Section IX to deal solely with unorthodox traveling effects, skipping more traditional methods on purpose.

20. ## Re: Planewalking – a guide for bending time and space

Originally Posted by Chalhubard
Hm... I see some potential there. Especially the bit concerning Intelligent Items counting as creatures - if we could pop around all over the planes crafting intelligent items that can cast Planar Bubble a few times a day... you see where I'm going.

On the plane shift/teleport subject, I've renamed Section IX to deal solely with unorthodox traveling effects, skipping more traditional methods on purpose.
Wow yeah, Planar Bubble ing Int Magic Items could be scary.

Oh yeah, also theres Banishment as a planar travel effect.

If your Construct is made on another plane it technically gets sent back there when its hit with Banishment right?

Same for a material Plane traveler wandering the planes. Contingent Banishment could make for an interesting method of going home when the conditions are met.

21. ## Re: Planewalking – a guide for bending time and space

This is a quite nice guide.

You might want to discuss the use of 'static'. It sounds like an Initiate of Mystra with Vestments of Steadfast Spellcasting could precast a Planar Bubble to enter a static dead magic limited magic[all] timeless[magic] plane to setup a contingent resurrection/simulacrum/intelligent item that is native to the plane. At that point, casting Planar Bubble on the native makes it and possessed objects nigh-invulnerable on any plane they should visit while layering on desired additional permanent spell effects including offensive auras or retributions.

22. ## Re: Planewalking – a guide for bending time and space

Originally Posted by unseenmage
Wow yeah, Planar Bubble ing Int Magic Items could be scary.

Oh yeah, also theres Banishment as a planar travel effect.

If your Construct is made on another plane it technically gets sent back there when its hit with Banishment right?

Same for a material Plane traveler wandering the planes. Contingent Banishment could make for an interesting method of going home when the conditions are met.
True, although still bound by the same sort of restrictions that regular planar travel would be. Was trying to gather a few methods to work around dimensional anchoring, but perhaps banishment-like effects could be an interesting trick up one's sleeve.

Originally Posted by Anthrowhale
This is a quite nice guide.

You might want to discuss the use of 'static'. It sounds like an Initiate of Mystra with Vestments of Steadfast Spellcasting could precast a Planar Bubble to enter a static dead magic limited magic[all] timeless[magic] plane to setup a contingent resurrection/simulacrum/intelligent item that is native to the plane. At that point, casting Planar Bubble on the native makes it and possessed objects nigh-invulnerable on any plane they should visit while layering on desired additional permanent spell effects including offensive auras or retributions.
I was about to comment on the Planar Soldiers of Mystra, but then I read your signature

On Static planes, there is a small if clause:

Spoiler
Static
These planes are unchanging. Visitors cannot affect living residents of the plane, nor objects that the denizens possess. Any spells that would affect those on the plane have no effect unless the plane’s static trait is somehow removed or suppressed. Spells cast before entering a plane with the static trait remain in effect, however. (emphasis added)

Which means one would be able to bash people around (which, luckily, for a proper caster, is no issue at all). So, yes, this is quite the nice trick, Anthro, thanks for the idea!

As for tackling on this sort of strategy, the only thing I can come up with is superposing planar areas to damage the source of the Static bubble, as the damaging effects would be 'natural', thusly not being subject to the "visitors cannot affect living residents" clause - this also raises the question whether Undead and Constructs would be ruled out as they are not 'living' residents. So much for using intelligent magic items as focuses for Static Bubbles.

23. ## Re: Planewalking – a guide for bending time and space

Originally Posted by Chalhubard
...

...

As for tackling on this sort of strategy, the only thing I can come up with is superposing planar areas to damage the source of the Static bubble, as the damaging effects would be 'natural', thusly not being subject to the "visitors cannot affect living residents" clause - this also raises the question whether Undead and Constructs would be ruled out as they are not 'living' residents. So much for using intelligent magic items as focuses for Static Bubbles.
Arguably Greater Humanoid Essence conveys the living status along with the Humanoid type if that helps.

24. ## Re: Planewalking – a guide for bending time and space

Originally Posted by unseenmage
Arguably Greater Humanoid Essence conveys the living status along with the Humanoid type if that helps.
Well, another question--What happens if the Int. Item is polymorphed? Does it lose its powers?

25. ## Re: Planewalking – a guide for bending time and space

Originally Posted by Thedez
Well, another question--What happens if the Int. Item is polymorphed? Does it lose its powers?
A very good question. Gets weirder if its also a Figurine of Wondrous Power.

Int Magic Items are weird.
Imma haveta start a handbook on them sometime.

I wonder if theres an old Rules of the Game article on them?

26. ## Re: Planewalking – a guide for bending time and space

Originally Posted by unseenmage
A very good question. Gets weirder if its also a Figurine of Wondrous Power.

Int Magic Items are weird.
Imma haveta start a handbook on them sometime.

I wonder if theres an old Rules of the Game article on them?
See, I'm half-glad the answer is 'I dunno," because that leaves room for the interpretation that we could PAO the intelligent item into a living creature.

27. ## Re: Planewalking – a guide for bending time and space

I didn't see any mention of incantations, and I tend to be obsessed with those. Two of the published ones are relevant. The first, Call Forth the Dweller, summons an eldritch horror to answer questions about doors (or other such things, like portals for instance). It can give you hints about what is beyond, the key, who made it, etc. It is pretty useful in adventures where the travelling is done through external, to the characters, means. The second is Hrothgar's Journey which, well, burns down your house and takes you (and your party) to Ysgard. Which is kinda situational, but it's planar travel nonetheless.

Other that that, I was always interested in the subject of planewalking, thanks for telling me the dark of it.

28. ## Re: Planewalking – a guide for bending time and space

Originally Posted by Chalhubard
I was about to comment on the Planar Soldiers of Mystra, but then I read your signature
The difference your guide makes apparent is that it may be possible to use Limited Magic[All] as well via the Ring of Free Magic. That adds yet another layer of planar trait based protection.

Originally Posted by Chalhubard
this also raises the question whether Undead and Constructs would be ruled out as they are not 'living' residents. So much for using intelligent magic items as focuses for Static Bubbles.
Yeah, that's a good observation.

29. ## Re: Planewalking – a guide for bending time and space

For classes: how about the Jaunter from Expedition to the Demonweb Pits?

For creatures: Nightmare is right in the Core

For spells: how the heck Plane Shift/Greater Plane Shift weren't mentioned?
Also, Finger of Expulsion spell (Dragon #330), and Far Look feat - it causing effect of aforementioned spell if Wis=0

30. ## Re: Planewalking – a guide for bending time and space

Guide updated to include a few lines regarding Intelligent Magic Items/Animated Objects and Planar Bubbles - under the Offensive Casting section. Also, incorporated suggestions from Anthrowhale, Feantar, and ShurikVch. Thanks for the all good ideas, folks. Keep em coming!