Of course I'll make that sure. They will not stack more than a hundred times for sure. That shoudln't cause an error. (As the game field is just 100 squares and after every single square has been shot it is sure that the game has ended). I mostly just use units for procedures and functions that I use often in other programs too (like a weighted mean calculation or a function maximum calculation) and as I progress with this game I have found other use of the "AI" object too but thanks this might be useful later on