Streamlining the Combat System

[The Anarresti]

I am about to DM a campaign set in the Ishka (http://www.giantitp.com/forums/showthread.php?t=120354) setting, which is basically a massive, multi-planar metropolis. My PCs are going to be a group of Shadow Martyrs, or Robin Hood types pulling of covert, daring stunts for the good of the disenfranchised. Fights are going to be plan B usually, as the focus is more on cleverness. Also, this is an urban setting: help is almost literally around the corner, so the characters can take much more damage and use up more resources on a fight than they could otherwise. On the other hand, local law enforcement, and cramped quarters were collateral damage is not an option complicates fights, removing things like area attack spell from the table.
In sum, I'd like fights to be vicious and quick, with an emphasis on ambush. Combat itself isn't going to be the focus of the campaign but more a means to an end. How can I streamline the combat system to reflect this?

[Glimbur]

What system are you using?

[derp, we're in the 3.5 subforum]

I find that what slows down 3.5 fights is option paralysis: PC's have so many different options to use that if they wait until their turn to decide it slows them down. Other offenders are Attacks of Opportunity and immunities, but in my experience it is mostly the players fault. Therefore, you could institute an "on deck" system where the next player knows they are next so they can start plotting. I like putting initiative on a dry erase board everyone can see. I have also heard good things about a turn clock. Everyone gets one minute (adjust to taste).

As for making ambushes valuable, 3.5 is already a question of who goes first. One spell from the wizard and the cleric before the other side moves can make the encounter much easier: battlefield control like Solid Fog, group buffs like Haste, and so on. Rogues also like surprise rounds for sneak attack. Even bog standard fighters have a better time of it because flatfooted foes often have a somewhat lower AC.

[Nashwolfe]

Therefore, you could institute an "on deck" system where the next player knows they are next so they can start plotting.

I like this, and use it as a DM, especially with certain players I know will take a long time to plan - very tactical players and spellcasters particularly.

Modifiers are also an issue; remembering which bonuses/penalties are in range/up/applicable can add a lot of time to initiative. ("Hang on... the bard song is up, I'm out of range of the Marshal, enemy is undead, is the bless still up? OK, I hit AC 21. Right, so it's my offhand dagger, half strength, bard song, I'll do slashing..." etc.)

As a player I make a point of doing the maths for each round while the previous player is making his rolls (I get through endless scrap paper this way). Of course, sometimes the mage blasts the guy I was creeping up on and it's all a waste :)

If you trust your players (and frankly I don't think any of us choose to play with cheats) they can make their rolls and get all the mechanical side of things out of the way even before their initiative, so when they come around they just have to tell you what happens.

As DM I've also been known to hint that while the players waste time, I'm reducing the loot table or toughening up the bad guys. I've never actually done so, but they get the idea, and it's become a running joke - "Shame the guy with the vorpal sword got away... anyway, you find 200gp".