HU you can't fold because you're more likely to be up against trips with a weaker kicker than you are to be against a full house. However with 3 players in the hand ( competent players ) you can do some card counting. On a AA3 board 3 players can't possibly have trip aces, so if the action gets heavy you have to slow down with trips. If you don't fill out on the turn ( and you're not already commited ) you can fold on the turn with only one card left to hit your kicker or pair the turn card. I've folded trip aces on the turn a few times, last one was a little different, the guy had a flush. I folded recently on the turn in a 3 way pot, no flush or straight showing. AA57 other 2 players raising and reraising, figured if one of them has an ace and i have an ace the other guy has to have 55 or 77. Sure eneugh the guy had 77. I let the other ace pay him off.