Having fun with hordes of monsters

[Yora]

Something that is very often in all types of fictional media, is a small group of protagonists fighting back massive hords of week monster. But in a pnp game, such encounters seem very boring. You just roll attack and damage round after round after round, and get some non-threatening points of damage every now and then. There's no tactics involved and being round based, there's no sense of hurry either.
However, I don't want to give up completely on that idea just now. So let's open this discussion about making mass battles fun. What have you done in the past that made such encounters fun to play, and what things should a GM usually avoid?

[Tinydwarfman]

Every PC is a caster. The enemies are smart, but don't bear down on you with everything they have. Force the players to make tactical decisions.

[Skorj]

It helps a lot if the attacks come in waves. Each battle is small enough to manage, and the time between waves can be used to build the tension and sense of danger. Because the party doesn't know how many waves will be coming, and how strong the attackers will become, taking a little damage and expending a few resources with each wave seems much more threatening.

Just in general, a fight that the party will almost certainly win is more fun if you can hide the fact that they will almost certainly win.

[enderrocksonall]

There are a couple of ways that I have come up with to make things more challenging and interesting.

Grenade-like weapons make high AC's practically worthless since they almost always attack touch AC. Touch AC is almost always below 20, so lower level spuds have less of a problem hitting.

Alchemist fire is great because it deals damage whether it hits or not. You can actually have the enemies just throw that stuff at the square the PC is in and it will deal 1 damage to everything in a 9 square cube, and the enemy only has to hit the AC 5 square. If you have 40 hurlers throwing every round, that can be a major threat to almost any group. And if you do have them throwing at the PC's directly, the PC's will have to spend a full-round action to put out their flames or else take an extra 1d6 every round.

Acid works well too, but it is basically a nerfed alchemist fire.

Also you can use the tanglefoot bags to slow down the party and keep them grouped together. This makes the alchemist fires even more deadly when they can hit more than one person. And even if the PC makes the save they are still forced into half movement if they don't want to waste an attack on the goop that is slowing them.

And the hurlers don't even have to be all that tough. My favorite is to do it with a group of about 15-20 kobolds and do it to a level 6 or 7 party.

For melee choads, the easiest way to return strategy to the game is the use of the aid another action and the feat spring attack. The best way that I have found to work this is to have a bunch of choads surrounding a single target, and they are all using the aid another action to boost the attack roll of a single attacker that is using the spring attack action to run in, attack, and run out.

If you have the choads using reach weapons you can stack up more of them on a single character. And you can make your spring attacker a higher level creature than the choads if you want so he can deal some decent damage with his highly probable hits.

For more inventive ways to make choad battles interesting, make give the PC's something that is the target of the attack other than themselves. After all, there are only so many of them and they can only be in so many places at once.

If the PC's are in a 15x15 open room that has 5 exits/entrances, and they must prevent the Golden Goblet of Goblin Supremacy from falling into the hands of the 80 (duh!) goblins outside the room, they are going to have a hell of a time preventing one of them from slipping in while they are otherwise engaged with the slaughter. Also a group of single hit point villagers can be a great target for choads.

Also remember that the aid another action can be used to boost a disarm check. PC's don't really get that much less powerful without their magical toys, but the psychological blow is enough that they will generally spend several rounds trying to get them back instead of trying to kill the enemies.

Also you can make a horde of low hit point, low damage dealing choads that, nevertheless, have a massive AC. One of the characters that I made for a friend's campaign can get his AC into the low 60's by sacrificing his attack rolls. So he never hits anything, but he never gets hit either. Believe me, its one of the most annoying tactics that can ever be employed.

Or take the opposite path and make tons of guys that have low AC and hit points, but deal TONS of damage.

Also attribute damage is always a nice, scary motivator for the PC's to end things in the most efficient way possible.

This is by no means an exhaustive list. A lot of these are just kind of abstract ideas that I have had and have not tested some of them, but the theory seems sound enough for the internet.

[Kosjsjach]

I've heard (but not experienced first-hand) that the Mob template in the DMG2 is a step in the right direction. I've also heard it has some failings, but a quick look-around will yield some homebrew fixes.

[reptilecobra13]

Low level guys can really benefit from buffing characters. Have a ton of low level minions and a couple of higher level (maybe on par with the PCs) boosters. Enemy clerics can really prolong a fight, and bards, marshals, or other boosting classes can dramatically change the power of a mob, especially when you can guarantee (thanks to some advance planning) that all of the buffs the baddies get will stack with one another. Things that can harm groups of enemies while boosting your mob are fantastic too. Think about a large group of undead fighting the PCs in an area that's been hit with an Unhallow spell earlier that day. Fun stuff can ensue.

[Thiyr]

Favorite tactic for making mass battles fun so far is...to toss them at low-level parties. Been running my first game for a bit, and against a level 1-2ish party, they are routinely outnumbered, usually 2:1ish. Not nearly as massive as some of what you're talking about, but my PCs have been enjoying it. Last one was particularly interesting for them apparently, because the goal for the enemies wasn't to kill them. It was to get them to the propper position to bullrush them into a few greased chutes. As the party's wizard was the first to discover the chutes, and then was pushed in before she could do anything, the fight got very frantic, very fast. Took the PCs a while to lose, though they took a fair number with them (and could have won if they didn't lose the wizard.) Terrain makes fights so much better.