1. Training first: if it’s your first time at FDA, the Weapons Master will give you a short, 2-minute training spiel for the rules and calibration for what level of force is appropriate in combat.
2. NO HEAD HITS, and no dirty hits.
3. When your opponent says “Freeze” your combat pauses.
4. When anyone says “Hold,” all fights stop.
5. Only up to four on one in a duel.
6. A ‘good hit’ is solid contact at the right level of force, depending on the weapon. Only these kind of hits count, and the person hit (not the attacker) makes the call.
7. A leg hit is anything at your hips or below, and means that you can only pivot (not walk) on that leg. You must stay in place, or very slowly drag the ‘injured’ leg. An arm hit is any part of the arm from the shoulder to the wrist (your hand is considered part of your weapon.) ‘Injured’ arms may not be used to wield weapons or shields.
8. When attacking someone who is legged, no circling. When surprise attacking someone from behind, you may not strike at full force (tap them gently and yell ‘Courtesy strike!’. This is still a good hit (and if it’s in the torso, they’re dead,) but safer.
9. Duels go on UNTIL someone receives a torso wound or three limb wounds.

A complete listing of the rules is here.