How can I make this even?

[WrstDmEvr]

I'm planning to throw 800 fighting kobolds against my 20th level party. The kobolds are going to be hiding behind stone barricades with an oping at the top for slings and lots of tiny holes for spears to be poked through in groups of 80 kobolds. At the very end,after they defeat the kobolds, they are going to meet a level 11 sorceror/IOTSV 7. The party consists of

Human Cleric w/ Fire domain

Drow Rogue/Assassin/divine spellcasting PrC

Human(?) monk

And maybe a ninja and a warforged. My question is, how can I make it so that the kobolds won't die within the first session or two? I'm not worried about the melee characters, but the divine spellcasters could easily beat those kobolds single handedly. And yes, I have read Tuckers Kobolds, for all those who will mention it.

[Xefas]

Perhaps if all the kobolds are also 1st level Warlocks (with the Eldritch Spear invocation), then 800 ranged touch attacks a round might deter the party slightly?

Nothing you can do to actually keep them ALIVE. I assume everyone in a 20th level party can fly, and many should be able to teleport and all sorts of things.

[Karsh]

Well, of your kobolds, unless you use the volley rules, every round out of the 800 attacks, 40 will hit, 2 of which are criticals. That's 44d3 damage, for an average of 110 damage. Not exactly going to mow down a bunch of 20th levels. Have them surrounded by every kind of trap imaginable, and hope the PCs are arrogant enough to rush them.

[Nerd-o-rama]

Send out the IotSV first.

Laugh at your party as they die horribly to a cackling, invincible Sorcerer.

Have the kobolds throw a massive kegger to celebrate.

[Raum]

My question is, how can I make it so that the kobolds won't die within the first session or two? I'm not worried about the melee characters, but the divine spellcasters could easily beat those kobolds single handedly. And yes, I have read Tuckers Kobolds, for all those who will mention it.

Use the terrain in the kobolds' favor. Don't fight a static battle from behind barricades, make it a running battle in tunnels too tight for the PCs to easily move in - if they don't start using reduce person spells the tunnels aren't small enough. But they do have plenty of spells so that won't be enough, have the kobolds collapse or partially collapse tunnels on & around the party. Make the terrain inside those tiny tunnels rough at best. Flood the low tunnels at opportune moments. Use cover, the PCs should seldom see the kobolds before an attack. Finally, use traps. Not just traps set off by the players but traps triggered by kobolds left behind specifically for the purpose. Kamikaze charges by kobolds with vests layered in vials of alchemical fire, acid, or poison gases are the simplest form of this...more elaborate traps in prepared areas being triggered by an observing kobold may run the gamut from deadfalls or pits to alchemical or magical attacks.

A 20th level party should still go through the kobolds but it will take time and a few resources.

[Lord Tataraus]

Use cityscape mob rules. The kobolds act as groups which are considered swarms and you just keep adding kobolds to boost the CR.

[WrstDmEvr]

Perhaps if all the kobolds are also 1st level Warlocks (with the Eldritch Spear invocation), then 800 ranged touch attacks a round might deter the party slightly?

Nothing you can do to actually keep them ALIVE. I assume everyone in a 20th level party can fly, and many should be able to teleport and all sorts of things.

The main weakness of the party is that they have no arcane magic at all. So, no flying, teleportation, etc.

Send out the IotSV first.

Laugh at your party as they die horribly to a cackling, invincible Sorcerer.

Have the kobolds throw a massive kegger to celebrate.

I almost died laughing when I read that

Use the terrain in the kobolds' favor. Don't fight a static battle from behind barricades, make it a running battle in tunnels too tight for the PCs to easily move in - if they don't start using reduce person spells the tunnels aren't small enough. But they do have plenty of spells so that won't be enough, have the kobolds collapse or partially collapse tunnels on & around the party. Make the terrain inside those tiny tunnels rough at best. Flood the low tunnels at opportune moments. Use cover, the PCs should seldom see the kobolds before an attack. Finally, use traps. Not just traps set off by the players but traps triggered by kobolds left behind specifically for the purpose. Kamikaze charges by kobolds with vests layered in vials of alchemical fire, acid, or poison gases are the simplest form of this...more elaborate traps in prepared areas being triggered by an observing kobold may run the gamut from deadfalls or pits to alchemical or magical attacks.

A 20th level party should still go through the kobolds but it will take time and a few resources.

This seems the best method of fighting so far.

Thanks for the comments everybody.

[Xefas]

The main weakness of the party is that they have no arcane magic at all. So, no flying, teleportation, etc.

Wait...they have no Boots of Teleportation or Wings of Flying or any magic items that let them do that?

Perhaps the Kobold Sorcerer should get some mass fly spells, and raise his army into an air force, all of which just pepper the party from 100ft in the air with some bows.

[Atanuero]

My idea would be to make the sorcerer rich, rich enough to equip and powerful enough to build the very best in equipment, terrain, and traps. make the kobolds fight like stereotypical elves in a forest: trap, retreat, trap, retreat, etc. If your party aren't rules lawyers, make traps and doors very, VERY difficult to defend against or get through-mostly by not using stuff in the rules. Don't write up stats either-just think of a few things that CAN stop or destroy it, then tell the party that everything else fails as they think of it.

Roleplay exhaustion on the part of the party-they may be 20th level, but they're not automotons. Make them rest before they run out of spells, then have the sorcerer dispel/remove somehow the protective magic and overpower them. Be really cruel and play lots of tricks on the party. Even 20th level characters shouldn't be able to assault a great kobold fortress and just walk through it as if it was their king's hall. To justify all of this, give the Sorcerer ridiculously high Int and/or Wis, because the Kobolds can't think of all this stuff by themselves, much less pay for it or do it properly.

Think of things real-life commanders do (or did) when defending a fortification: have some ranged fighter kobolds and employ sniper tactics. Make the arrows induce paralysis, and run the cleric out of healing, forcing them to rest more often. Pull out some of the really devious traps that all DMs have lying around for future campaigns.

Use some or all of those suggestions depending on how long you want this battle to last and how 'epic' you want to make this assault.

[Armads]

Okay, this is sad. The party will have a hard time surviving if your kobolds follow the Missile Volley Teamwork Benefit in the PHB2. Basically, all the kobolds (with Point Blank Shot) make 1 attack (they have only 1, anyway), and a level 3 kobold with Far Shot and Precise Shot makes another attack (it could be a level 2 kobold fighter with those feats). All the kobolds gain a +800 bonus to hit. So 40 attacks will miss, 40 will score critical hits (x3 crits, at that), and the remaining 760 will hit. If you r players have DR, then the whole kobold thing won't work, though.

[WrstDmEvr]

There are going to be 10 groups of 80 kobolds, and of those 80 at least 4 hit due to natural 20's. There are 2 groups of poison arrow archers, 4 groups of regular archers, 2 groups of suicide kobolds(Thanks, Raum), 1 group for defensive purposes and 1 group in reserve for when they need it. After that, they face the sorcerer. I'm not using Missile Volley Teamwork Benefit.

[leperkhaun]

make a couple trap/ambush points. Kobolds are master trapsmiths. As another suggested you could use mob rules for ones you send against the party. other than that.... maybe a couple class levels, if you dont a couple of cloudkills (or similar spells) will make the encounter non existant.