Invasion is a simple wargame concerning a hypothetical invasion of England by an unnamed enemy. The map shows a square grid superimposed on a map of southeast England, the Channel, and a small section of France and the North Sea (there is a Channel tunnel, interestingly enough). Each player has a small number of men (14 for the English player, 12 for the enemy player) which move from square to adjacent square, or farther if using railway lines. Pieces on adjacent squares may be captured. The enemy player's objective is to move a piece into London, the English player's to capture all the enemies before this happens. There is an "extended" set of rules which turn this basic abstract system into a bit more of a wargame. Naval movement is now differentiated from land movement (and much faster), the English player may make greater use of the railways than the enemy player, pieces require support to capture opposing pieces, etc. It is also suggested that an umpire be used so that each player only knows the position of his or her pieces. The game was originally published by F. H. Ayres in a book, Handbook of REVERSI and other new GAMES of SKILL. INVASION. HALMA. FANORONA. Explanations. Rules, Problems and Suggestions to Players, and also in a boxed version (publisher unknown). The book version was reprinted in Sid Sackson's game column in Strategy & Tactics #21, from which all this information is taken.