Edges

Players take turns to place the triangular pieces onto the board. When played the piece must be laid down so that its edges match those of any piece already in position (i.e Red to Red, Green to Green).
When two or more edges are matched the player earns an extra turn. If a player cannot place a piece matching the edges then the turn is forfeited and play reverts to the opponent.
When one player has placed all the pieces on the board the game is over and opponent calculates the penalty points for the unplayed pieces. If no further play is possible then both players calculate the penalties for their unplayed pieces.