Howdy, I've been using MASON for a while - love it, thanks so much for what you're doing. I've hit a bit of a snag with Bag, and I could use some help. I have agents playing a game, and I used getNeighborsMaxDistance to find possible players. Each agent has a boolean variable played - only agents whose played = false should be available as potential partners. For debugging, I created a situation with 3 agents occupying a single spot. First, two of them should play, and then the next one should find no one to play with. However, that last one kept returning with a partner who had already played. Here is the method: public Bag findNotPlayed(Bag neighbors){ for(int k = 0; k < neighbors.numObjs; k++){ Agent a = (Agent)neighbors.get(k); if(a.equals(this) || a == this){ neighbors.removeNondestructively(k); break; } } int num = neighbors.numObjs; for(int i=0; i < num; i++){ Agent a = (Agent)neighbors.get(i); if(a.played) neighbors.removeNondestructively(i); } return neighbors; } In the second for loop, when I used i < neighbors.numObj, the method removed only one of the two agents who had played. When I substituted the local variable num, I got a IndexOutOfBounds exception. What I really want is to make sure that the second for-loop is going through every object in the Bag, and removing ALL the relevant objects. I've tried both remove() and removeNondestructively - it doesn't seem to make a difference. Any ideas? Your help is most appreciated. Thanks! -Paul