Knockout is a game in which you compete against the Spectrum or up to three other players, and is effectively a computer version of the popular board game 'Rebound'. The object is to bounce balls around a board and leave them within firmly defined scoring positions. Each player has four balls to a frame and opponents take it in turns to play each ball of the frame.
The screen display shows a plan view of the board with black walls bent in the shape of a tight G, the ball being shot from the top right end of the G, rebounding off the end walls and ending up in the tail of the G where there are two blue areas of scoring and three green higher scoring areas before a yellow out of bounds.
The player's ball (up to four different colours) is positioned vertically for its shot, an angle determined, and a strength of shot by onscreen prompts and the cursor keys 6 and 7. The balls all remain in play until the frame is completed so there is the chance of knocking an opponent's ball, or your own, into better or worse positions for scoring. Players enter their names at the start of play and the computer scores for each and keeps a running total. If you are on your own and only enter one name, then you will be playing against the computer.