For each one of these totally unnecessary rules you add, reduce the base AC of your game by -1
- Shoes grant +1 AC when worn. Having your shoe sucked off by quicksand or destroyed means your feet are more vulnerable, making an easy target.
- As long as you're wielding a melee weapon, gain +1 AC. You can use the weapon to parry and deflect blows. Alternatively, this only applies to weapons longer then a dagger.
- If your character is fully clothed, add +2 AC. Reduce base AC by 2 instead of 1. Skimpy clothes like loincloths only grant +1 AC
- Fighting with any kind of protection for your head (hat or helmet) grants +1 extra AC. You need this to keep the sun out of your eyes, and to avoid your hair being grabbed.
- If you're fighting in a uniform or under war banner; you get +1 AC. Fighting with a group makes you more intimating and less likely to be singled out- zebra logic.
- If your character is clean shaven or well groomed, they get +1 AC. Fighting while dirt or unwashed is a disadvantage, you're more likely to get caught on things or your own hair being used to grab and put you in a dangerous position.
- If you're fighting in a lighting condition that favors you, gain +1 AC. This isn't exactly the same as a negative modifier to enemies striking you, you have better footing. Orcs and subterranean creatures get +1 AC in darkness, surface dwellers get +1 AC in light.
- If you're dry, warm, and not savaged by the elements gain +1 AC. Characters who get wet or bogged down by flies or otherwise disadvantaged by nature carry this into combat. Bit of a play on the idea of using things like “Freezing cold” or “Wet” as a negative condition that fills an inventory slot, ala Skerples or Goblin Punch.
I have no idea why I wrote this. You could also use the above as a 1d8 table.