(advice) How many kobolds does it take to tpk a 3rd level party?

[Dwimmerlied]

I'm planning out some kobold mines through which 5pcs of around 3rd level will be passing. On their first visit, the kobolds are not expecting them, though I plan to use sentries to bring rapid reinforcements in an attempt to swamp the pcs. On their second visit the kobolds will be far more organised, and I'll be taking a leaf or two from Tucker's memoirs.

I'm planning to take the kid-gloves off; my thinking is that a robust party of 3rd level characters should be able to handle just about anything a kobold has (stats-wise).

So my second run will present the characters with every kobold trick in the book, chemicals, explosives, scorpion venom, etc etc. But for the first run, if I'm using kobolds, armed only with half-spears/javelins and standard combat maneuvers (flanking, cover, aid another etc), how many is too many? Is there such a thing? Have you ever run an encounter like this?

 

[Quickleaf]

I am not an experienced 3e/Pathfinder DM so in a straight fight I don't know.

However I have 12+ sessions of experience with kobolds in 4e and I know what the answer to that question would be not in a stand up knock down fight:

One. One kobold "guide". And a hell of a lot of traps

 

[delericho]

42.

No, seriously.

Kobolds in 3.5e are CR 1/4 (IIRC, in 3.0e they were 1/6). This means that 4 kobolds make for an EL 1 encounter for 4 PCs. But, since you have 5 PCs, you should similarly increase the number of enemies. So, our baseline is 5 kobolds for 5 1st level PCs.

But, of course, your PCs are 3rd level, and you're looking for an "overwhelming" encounter - that is, one that has an EL more than 4 above their level. So, you want something more than an EL 7 encounter.

So, if you double the number of kobolds (to 10), you get EL 3. Double again (20) and yet again and you get 40 kobolds for EL 7, right at the threshold between "tough" and "overwhelming".

So, you want more than 40 kobolds for your encounter... hence 42.

 

[delericho]

Of course, the above assumes that the CR/EL system works as intended. And we know that one of the areas where it breaks down most clearly is when you use it to send lots of very weak creatures against more powerful PCs.

Fortunately, by 3rd level, PCs tend not to have the powerful "crowd control" spells available to them - the Wizard doesn't get fireball for 2 more levels. So this example may just sneak in before that bit of the system breaks. My gut feeling is that you would actually need rather less than 42 kobolds to score a TPK.

(And no, I've never run an encounter quite like this. When I've done the "heroes vs horde of weak enemies" thing, it's been at a higher level, and has been done to highlight just how powerful the PCs have become - where it's basically played out like The Bride vs the Crazy-88 (Kill Bill, of course).)

 

[knottyprof]

There are feats in one of the splat books (complete warrior maybe) that allows small creatures to double occupy a 5 ft space. I would give this to the kobolds as well so they can double up on the PCs if they are doing a direct assault. Of course, kobolds are typically cowards at heart so if they are expecting intruders they would probably set up a ton of traps instead so the quantity of kobolds matters only in trying to determine how many traps can be set before the party arrives. Also, traps can be organic. Maybe the kobolds lure a larger monster or animal into the mines and allow the monster to deal with the party as well.

 

[ImperatorK]

Depends on your PCs.

 

[N'raac]

Depends on your PCs.

Very true. L3 - let's say a fighter in full plate, large shield, 12 DEX. That's AC 22. The Kobolds need a natural 20 to hit him (19 if they can flank, but he should be smart enough to back to a wall). Let's assume he has a 16 STR and a +1 sword. +7 attack bonus means he hits their AC 1 on an 8+, so 35% of the time he misses. He does 1d8 + 4, so one hit drops a kobold. Back to the wall probably lets 4 of them get at him at a time (8 if we let them double occupy a 5' square), so they should hit every 5th round (2/5 rounds) for 1d6-1 (2 2/3 on average). He takes about 65 rounds to drop the bunch. They can do about 35 damage (70), ignoring the fact there will be less than 4 (8) in the last few rounds. That's likely moere hp than he has. Of course, we have ignored his 4 teammates, and any useful feats he may have. 42 kobolds seem a lot less overwhelming.

Min you, letting the party kill of such an "overwhelming force" with seeming ease will make it sting that much more when the kobolds are prepared with traps and sneaky tricks...

 

[Dwimmerlied]

Nice, deep analysis. Thanks guys! Re; the swarmfighting feat, I just noticed that today and decided its a must. For a little more information, my players will be relatively new, with only a few sessions under their belt, but a good mix is presented. So far, (a really dumb) half orc barbarian, a human fighter, a wood elf 2handed fighter, an elf wizard and a half-elf druid. Perhaps a halfling rogue will join them. None are overly optimised at all.

The basic set up so far is, on their first foray into the mines, catching the kobolds relatively unaware, the standard encounters will be something like this;

20 kobolds armed with slings on scaffolding 20ft high. Their attack is only +3, and I think that they do only 1 or 2 damage on a hit. But the interesting thing is that they can concentrate attacks on one character at a time if they wish, and will do so particularly when someone attempts to climb the scaffolds. Even 1hp damage forces a climb check, and failure results in falling.

I think that given 2 rounds, characters could overcome, say 10 (if the wizard uses something like sleep, the fighter types hit every round and the others hit once in two rounds). Of course, this could be quite swingy...

The second element is that there is a gong that can be sounded that can bring up to 20 more kobolds (but often less) in 2 rounds from existing chambers. Further, one kobold assigned "sentry" can flee to another nearby mine and perhaps recruit more. Clever characters who spot this have a chance to stop it though.
@N'raac ; regarding your last sentence: this is my devious plan. The second visit will see the kobolds become very devious indeed...
[MENTION=22424]delericho[/MENTION]; Yeah I kind of anticipated the math would fall apart past the first couple of "doubling monster numbers adds +2 CR." I agree with you that the absence of crowd controls will make this much better!

 

[(Psi)SeveredHead]

It's dependent on numerous factors.

If you could lure the PCs into a "trap", say large tunnels or rooms with no cover, and lots of concealed arrow loops, plus 20 to 40 kobolds all firing crossbow bolts through them, and maybe a kobold sorcerer or two. Traps are fine, but not pit traps, as scared PCs might actually take shelter in them. This could be standard practice; there's a reason the weak kobolds have managed to survive for so long.

Note: The arrow loops have to be concealed! The PCs need to walk past half of them before the ambush starts, otherwise they'll escape.

Are you serious though? Is this an actual TPK attempt?

 

[N'raac]

Back to the "depends on characters", one of the most frustrating things I find for optimized "one strike damage" characters is swarms of little enemies. OK, your 20 STR Power Attacked Greatsword strike hits one kobold for 18 damage carving it in half. Now the other 7 surrounding you get to attack. I'd think, if the party takes out 10 of 42 kobolds in a couple of rounds, especially if the kobolds have accomplished little visible harm, the other 30 are not going to stick around to fight...