The Simplest Bounce
There used to be a block called 'Bounce' in older versions of GameMaker. It no longer exists, but can easily be re-created with 1 line of code.
1. set up room with ball and wall objects:
2. Code objBall Create event to randomize direction every time the game is replayed:
3. Code objBall Collision event with objWall to simply bounce using 1 line of code: move_bounce_all(false);