This is an unusual, to say the least, variant on chess. Instead of moving pieces in a set fashion, the pieces are flicked at the opponent's, using thumb to hold back index finger, and releasing it, once aimed, in order to fire the pieces at the opposition's. It takes its name from the hobby-game Subbuteo, where the aim is to flick miniture plastic footballers at the ball in order to score goals.
Each player has one flick per turn. This may be used on any piece that the player has control of. The flick may be aimed anywhere on the board. If the piece leaves the board, it counts as a casualty. If it lands on the board, but on its side, it is placed upright on the square that has the majority of the piece resting on it.
If the piece knocks over one or more enemy pieces (for the sake of quick typing, I am including both pawns and the king as pieces), those pieces may become casualties. The rules vary here. Some of the more beginner-friendly versions say any piece, except the attacker, counts as defeated. Some use the existing points system in chess to determine casualties. Some use a set of 'wounds' that are suffered before the piece can be killed. The majority kill any piece that is knocked over, including the attacker.
The objective, as in normal chess, is to defeat your opponent's king, generally by causing it to be counted as a casualty. Sometimes this is changed to killing all your opponent's pieces, sometimes within a time limit. Your opponent will be either trying to kill you first, or just trying to survive long enough. Since many casualties are caused by flicking your own pieces off the board, there can be rewards for keeping pieces alive after shots. Most just go for the king. Since it is possible to kill your opponent's king or queen with just a single, well-aimed pawn on the first move, a lot of the game focuses on defending quickly - a sort of anti-rush strategy.
There are two main ways to play the game - all-out attack or careful defense. One person tried to carefully move pieces into position like in a real chess game. Needless to say, he didn't last long.
Unlike in real chess games, the centre squares hold much less power, since a skilled player can send any piece anywhere from anywhere. However, the heavier pieces are still important, as their weight means they resist attacks better, and their greater momentum means they can knock more pieces down at once. For this reason, an actual Subbuteo chess set, if anyone ever makes one, should have a heavily weighted king, so it takes skill to knock it down and win the game.
Classical chess maneuvers, such as the pin, fork, and skewer still work - but are much harder to perform. Discovered attack is useless - it is simpler just to use the front piece. Scholar's Mate is irrelevant, and is replaced by several quick pawn-attack systems.