Looking to make a hard battle for my group

[xenosus]

I want the CR to be 16-18 and it to be only one guy they fight. His alignment is LN and is going to be the equivalant to a pope of his church.

The game is based in a planes walking setting and the players are trying to find an obelisk to push out the god of this plane and inundate their own god as the supreme ruler of the plane. A big theme for this plane is lots of ridiculus rules set in place and machines and golems, lots and lots of golems.

The player's current level is 12 and there are 3 of them. We have a power gamer wizard as well.

I'm thinking of having a unique terrain as well, like moving platforms or conveyors or scales forcing players to seperate or something entertaining while making it harder on the players like for example a sphere of law to give some negatives to the chaotic characters or something.

[00dlez]

It sounds like you already have a pretty good idea of what you are hoping to do.

One enemy can often go down quickly against an organized group, so be wary of the party's ability and your opponent's weaknesses. Even a 4 CR advantage enemy can go down in a round or 3 against a prepared party.

[xenosus]

hmm, maybe a cr 20 then? or just stick with 18 and go with the bad terrain for the players.

[Kelb_Panthera]

"Power gamer wizard" is a huge red flag.

Is he consistently the key to victory?

If so, then perhaps make it a two enemy encounter with one of them counterspelling the wizard.

I'd need to know more about the party's composition and tactics to give any further advice, and I imagine that goes for most others that would try to help too.

[Crinias]

What's the wizard's usual strategy? What spells outside core does he have? Does he have a prestige class?

[docnessuno]

Just a basic sketch:

Human - Half Stone golem
Cleric 6 / Techsmith 10
CR 19

Unbuffed stats:
Str 22, Dex 12, Con 20 Int 10, Wis 24, Cha 8
AC: 34 (1 Dex, 9 Armor, 3 Shield, 9 Natural, 2 deflection) (To 13, FF 33)
HP: 6d8+10d6+80 (142)
Immunity to magic (as stone golem), DR 10/adamantine
Casting as a lvl16 cleric, plus construct-related goodies and construct companion.

Feats:
Skill focus (craft: blacksmithing)
Craft magic arms and armors
Improved iitiative
Extend spell
Persistent spell
Divine metamagic (persistent spell)
Extra turning

Items:
Gloves of Str +2
Amulet of Con +4
Periapt of Wis +4
Ring of protection +2
Cloak of resistence +4
+1 Heavy fortification adamantine full plate
+1 Animated adamantine large shield
+1 Spell storing Adamantine spear
2 Nightsticks

Tactics: Standard DMM CoDZilla. Magic vestment x2, Greater magic weapon, DMM persistent Divine power, another DMM persistent spell, persistent Divine favor, persistent protection from chaos, other lvl1/2 persistent spells depending on allowed sources. Enjoy critical immunity, Dr and Magic immunity. Obviously only buffs without SR can be used.

[Biffoniacus_Furiou]

Human, middle-age, LN, Archivist (http://www.wizards.com/default.asp?x=dnd/ex/20051007a&page=3) 3/ Church Inquisitor 3/ Divine Oracle 4/ Sacred Exorcist* 1/ Contemplative 7; CR 18
*Sacred Exorcist adapted to fight chaos instead of evil, replace good prerequisite with lawful, Dispel Evil with Dispel Chaos, etc.

Two flaws, neither of which will have any impact on his battle with the PCs (healing spells do half as much for non-LN targets, suffer arcane spell failure for armor/shields when casting divine spells).
Bonus Feats: Skill Focus: Kn: Religion via the Frog God's Fane.
Feats: Extend Spell, Persistent Spell, Fell Drain Spell, Law Devotion, Knowledge Devotion, Exotic Shield Proficiency: Gnome Battle Cloak, Improved Counterspell, Quick Recovery, Divine Defiance, Invisible Spell.
Skills: Max ranks in Spellcraft, Concentration, and most Knowledge skills which pertain to identifying creatures of a given type, especially Kn: Local for Humanoids.
Skill Tricks: Collector of Stories, and anything else which would be relevant.
Special: Through intense study and much personal investment, this individual has unlocked and gained the benefits of the Mastery of Counterspelling high arcana of the Archmage prestige class.
Every spell he ever casts is with Invisible Spell, no exceptions.

Magic Items: Blessed Book, Ring of Enduring Arcana, standard Strand of Prayer Beads, Reliquary Holy Symbol, two Lesser Metamagic Rods of Extend, Third Eye: Clarity, Sandals of the Vagabond, Masterwork Gnome Battle Cloak with Crystal of Bent Sight attached, Circlet Clergy Hat of Rapid Casting with a +4 Enhancement bonus to Int added, Clergy Robe with +1 Soulfire as though it were armor. Personal Permanency spells: Tongues, See Invisibility, Darkvision, Detect Magic. Local Permanency spells: Alarms, Private Sanctums. There's also a local Lawful version of Hallow with a Freedom of Movement attached, set to only benefit those of his own faith.

Daily Spell Buffs (with Bead of Karma): Extended Superior Resistance and five Extended Energy Immunity every other day (three spell slots per day spent, 7th), Mind Blank (8th), Primal Hunter (1st), Primal Instinct (2nd), Primal Senses (3rd), Primal Speed (4th), Persistent Swift Fly (9th), Persistent Swift Haste (8th), Snowsight (1st), Heart of Air (2nd), Heart of Water (3rd), Heart of Earth (4th), Heart of Fire (5th), Mage Armor (1st), Magic Vestment: Mage Armor (3rd), Magic Vestment: Gnome Battle Cloak (3rd), Moment of Prescience.

Tactics:
Prior to combat (If alerted to the intruders' presence by his Alarm spells): Cast Foresight, (Extended:) Barkskin, Shield of Faith, Nightshield, Ebon Eyes, and Sign. Cast Deeper Darkness and then (Extended) Silence on a coin, place it on a saucer on his desk/table, and set a cup over it blocking both spell effects. Concentrate on Detect Magic when the PCs enter, count the number of auras/spells present on each individual (his inhuman intelligence will easily permit this).
Initiative: Use Moment of Prescience for +22.

First/Surprise Round:
Standard+Swift actions in order: Cast Time Stop, cast Choose Destiny; cast Fell Drain Fire Shield, Rapid Cast Fell Drain Cloud of Knives; cast Greater Invisibility, Rapid Cast Fell Drain Spiritual Weapon; cast Fell Drain Spiritual Weapon, Rapid Cast Fell Drain Spiritual Weapon (twice); keep casting Fell Drain Spiritual Weapon.
Move actions in order: Ready shield (battle cloak), pick up the saucer holding the Silence + Deeper Darkness coin shielded by the cup, move into the air above opponents and drop the saucer and cup, move higher up and a bit to one side and keep moving each round.

Note that the first move action will be paired with Fell Drain Fire Shield during a surprise round, or it will be paired with Time Stop in a normal round. Also remember that even if a spell takes a higher level slot due to metamagic, it's still considered a spell of its original level for all effects, including metamagic rods and the Circlet of Rapid Casting. If he doesn't have enough rounds during Time Stop to get all of those cast, he should finish the sequence in the next few rounds of combat, possibly delaying the swift actions to use Divine Defiance to counterspell anything that would reveal him or disrupt his attacks. Most/all of those 1 round/level spells should be Extended, either via a Lesser Rod or just normally to spread them around a few spell levels' slots.

He should aim the Cloud of Knives attacks at any opponent looking at him or otherwise visibly aware of his location, if none then target anyone holding a ranged weapon. His Spiritual Weapons should each be targeted at a different opponent until there's one on each, then start putting extras onto anyone with a spell component pouch and/or a holy symbol or other divine focus. Remember that the Spiritual Weapons are invisible, and should be treated as from an invisible attacker.

Future rounds can be spent using targeted Greater Dispel Magic on opponents with a lot of magic auras, then Extended Fell Drain Creeping Cold on each opponent, and/or Fell Drain Heat/Chill Metal on opponents' weapons so they drop them. If there are a lot of opponents he can use (Fell Drain) Black Tentacles and even Call Avalanche. If multiple opponents can see through both his Deeper Darkness and his Greater Invisibility, he can use the cheesy Obscuring Snow which he can see through due to Snowsight.


Yes, this is a wildly difficult battle that is extremely likely to kill everyone, CR 18 is no joke.