The 'percent to hit' system sometimes makes me groan; get up to hugging distance with a cryssalid, 94% chance of hit, miss, sniper with 70% chance of hit misses too, spout verbal abuse at computer. It used to bug me. But it does work both ways; had lucky moments where mutons across the map were blasted with alloy cannons, had another awesome moment today where my best sniper was saved from two cryssalids by newbie supports both scoring hits that only had a 20% chance. When I crunched the numbers, I couldn't believe it. Hooray for random numbers!