Fishbone said:Dangit, Haakon1 beat me to it. Kobolds are basically VC with scales.
Here is one thing I want to say, though. Kobolds should almost always start with 4 warrior levels as the base. That leaves them as a CR 1 creature with 4 HD. That also means that they have a good reason for having a lot of wealth. Pooled resources. Rogue 1 is cool and all but +4 to attack, better saves, another feat, and 3 times the HP(6-7 versus 18). They also qualify for martial prestige classes a lot quicker.
If you give them a level of Fighter on top of that they are only CR 2(4 NPC levels -3 for base CR, +1 from the Fighter level) and with ranged attacks they will be +4 from Dexterity(15+1+2 Racial), +4 from Warrior levels, +1 from small size, +1 from masterwork weapons. +10 attack before flanking, higher ground, feats, etc. With bows they could be pretty scary considering that they are such a low CR you can use a real boatload of them and with things like Point Blank Shot, Rapid Shot and the like they could be quite the handful. Or put Rogue 1 on for the skilled hit and runners. That should really scare the players. They're getting mobbed by lowly kobolds and not one shotting them. The kobolds attack them two or even three times. They'd have nearly 30 HP if you ran them like this!
NO! Says I.
Kobolds are supposed to be squishy. That's the driving reason for them to have tactics. Giving them multiple class levels removes the challenge as a DM. I'd say give non-leader kobolds 1 class level max, or just leave them as they are in the MM entry.
Can't hit the players' ACs? That's what the 'aid another' action is for. Make an attack against AC 10 to give +2 to another's attack. This is especially useful when combined with reach weapons and huge numbers. 20 kobolds can attack a single square at once if 12 are using reach weapons. Spears are simple weapons. Consider using the swarmfighting feat as well. The problem with fitting so many kobolds in a small area is the possible area attacks, or great cleaves.
Also, kobolds move as fast as the players (except for barbarians and monks). Another option is to have them fire and move each round. It will get very frustrating for the players, however.
If you want Real Classed Cheese (tm), give each kobold a level of sorcerer. If you have 10 kobolds per player, that's 10d4+10 damage per player, per round.
In other words, don't do it.