'flurry attack'
Flurry attacks are a passive effect granted by Kung Fu Mastery. Each time you hit with an attack, it gives you a small chance for a follow-up "flurry" attack. You can see which attacks are flurry attacks by toggling gag wflag. There is no limit on the number of flurry attack you may execute (a flurry attack may cause another flurry itself), but on average it will be less than one extra attack per round.