Interaction 1978

"The devious strategy game where each move generates a chain reaction."

The board is 9x9 with the corners clipped; the middle row is made out of deeper "pockets". Each player controls two cue balls; in addition, there are 10 neutral balls, moved by the cue balls. The object is to maneuver five neutral balls into the pockets (once there, they are removed for score).

On your turn, you pick a cue ball and launch it in one of eight possible directions. Your cue ball may travel any distance in a straight line before hitting a neutral (or another cue ball); at that moment, its momentum is transferred and the ball hit moves the same distance. Should you hit a row of balls, only the farthest one moves (as in a Newton's Cradle). All balls bounce off the play area's walls, either straight back when hitting head on, or reflected when hitting at 45 degrees. Note that a move that doesn't hit any balls is illegal.

Includes solitaire problems where the object is to find the least number of moves required.