[3.5] Help with urban warfare

[Meat Shield]

I will be taking PCs on a rescue and recovery mission in a city currently under attack (and falling). They will need to recover an item from the main temple of a god on that world, and rescue a cousin to their king.

Bad guys will have already gotten inside the walls, but will not have the two locations where the above are (yet), and there will be other areas where the buildings and blocks are held by friendlies.

Bad guys are hobgob and human heavy infantry, ogres/hill giants/trolls, and sufficient arcane/divine magical support to make it "interesting" for the PCs.

PCs are 10th - 11th level, mostly melee types. Paladin/warblade, paladin/crusader, swordsage/rogue, either a druid more interested in shapshifting than spells or a spellthief (player not made decision yet), a favored soul/archery swordsage-variant, and a to be determined member, but probably a mage of some sort (he will be 10th).

I have read Heroes of Battle, but want to hear about other experiences and ideas to make this truly challenging for my PCs. Its been a while since they felt truly afraid and faced failure. I want them for story purposes to be ultimately successful, but I want to make them sweat. Tell me about encounters, terrain ideas, whatever you can think of.

[c0r1nth14n]

Probably the worst possible place to have to fight in is the sewers. Dimly-lit, so cramped you have to go in single-file, trudging through water which can obscure traps or beasts or other nasty surprises... yea, make them go through a sewer. They will learn to fear.

[Graymayre]

Probably the worst possible place to have to fight in is the sewers. Dimly-lit, so cramped you have to go in single-file, trudging through water which can obscure traps or beasts or other nasty surprises... yea, make them go through a sewer. They will learn to fear.

Have a squad of elite kobolds in those sewers too. Make them all level 1 npcs, but give them a lot of time before hand to make that place a hell hole. For added flavor, name their leader "Tuk'hor".

[Tsotha-lanti]

Turning an urban scenario into a sewer scenario is a cop-out; instead of using the interesting urban terrain, you're turning it into a dungeon crawl in a spectacularly uninteresting dungeon.

Instead, use the city environment to good effect. Terrain can count for a lot. Archers on rooftops and in windows (divided so as to form a killing corridor and not be easily taken out with a single spell), spellcasters in towers and turrets, ad-hoc barricades, and so on.

Make sure the individual enemies are a threat on some level. If they have only a 1-in-10 chance of hitting the PCs, they're not really relevant in any way. Remember, levels are only abstract representations of the story importance (in this case, the challenge provided in combat) of NPCs / enemies. But don't just send wave after wave of melee mooks in - combine them with archers, shock troops, war machines, cavalry (nothing like being ridden down by multiple waves of lancers on a narrow street), spellcasters, and beasts of war.

Use randomly-timed (every 1d4+2 rounds, or X% non-cumulative or cumulative chance rolled every round) reinforcements; make a "wandering troops" table, and use it. Make the PCs feel the overwhelming press of numbers - if they get pinned down, they will be overwhelmed. Force them to keep on the move and be creative, and facilitate any cool ideas they have. Make them use stealth to avoid enemies altogether, because they know that fighting will bring in 2d10+10 more enemies every round. Don't let them rest - force them to ration out their spells and magic items, and make sure they know to stock up on wands and potions beforehand (but don't just hand them out for free; make them either part of the level-appropriate loot for the adventure, or make them spend their own savings on them - same difference).

[Graymayre]

The DM's Guide also has a table of random city events. During war, these would definitely spice up fights. Collapsing building and Fire are two that come to mind.

[Jayngfet]

Rooftops, streets, sewers. Thats three levels of city to take into account. There could always me some enemy jumping from a low roof or crawling out of a manhole. Not to mention from either end of the street or jumping out of a door. With some preparation they could shoot arrows from one direction to guide them into an alleyway with razor wire on one end, dump caltrops down the other, have bowmen pin them down from the roof, and a caster waiting in a nearby manhole cover with a summon monster spell or two.

[Rhiannon87]

All these ideas are good, but you really want to screw with them? Let them get to a safe location, among friends, who assure them that they can rest here for a bit, get healed, etc. Give them about three to five minutes of relaxation, then rain bloody hellfire down upon them. Make it a semi-secret location and imply that the party led the attackers to the place. Force them to basically run for their lives as the safe place is overrun.

That oughta break your paladin's hearts right there.

[Meat Shield]

Thank you everyone.

I have read some about the battle of Stalingrad, and hope I can convey that kind of vibe to my players. I don't think we will be going int othe sewers, but I should have something ready just in case. The PCs make liberal use of teleportation magic and maneuvers, which makes things difficult to predict how they will go, but I will do my best.

Also, there could very well be erynies and half-fiend shock troops about as well. Ideas on the effective use of ground attack aircraft and how to maximize their shock value?

And of course, more ideas to the original question in my first post please!