Rules

Rules are as per Pathfinder, with some changes:

Kobolds
Kobolds use the template described here, with the following changes:

Ability score modifiers: +2Dex +2Cha -2Str

Languages: Common, Draconic

Taking alternative racial traits is allowed, especially regarding "Crafty" if its bonuses do not suit your character.

In addition, if you wish, you can choose to lose the Crafty trait in order to also lose the -2 Str modifier. Every so often, a kobold is hatched larger and stronger than others, but this tends to lead them away from the tinkering and sneaking life and toward more physically demanding jobs, or ones where being an imposing, big guy (for you) has merit.

Equipment
Crossbows now inflict x3 damage on a crit and only count half of the bonus a target's armor gives to its AC, rounded down. For example, if a light crossbow is shot at a target wearing full plate at 80 ft or closer, the target's full plate only gives a +4 bonus rather than +9, and the target's AC is thus 14 rather than 19.

Variant Rules
This may be subject to change in the future if I decide something does or doesn't work well.

Called Shots

Piecemeal Armor - Note that this only affects loot. You don't have to list every individual piece of armor if you don't want to.