Invasion: America is a wargame designed by Jim Dunnigan and published by SPI in 1976. It depicts a hypothetical invasion of North America by a coalition of three invaders. The game is played on a 35 by 42 inches (89 by 107 cm) map, with 400 cardboard pieces representing the armed forces in the war. As is typical of wargames of this genre, each piece has numerical combat and movement ratings printed on it. The board is divided up into small hexagons (each of which represents approximately 50,000 square kilometres (19,000 sq mi)). On each turn a player can move all of his pieces through a number of hexagon spaces equal to its movement rating. Then pieces in adjacent spaces will engage in combat by comparing their combat ratings and rolling dice. The combat ratings and the dice roll are cross-referenced to determine the outcome of the combat. Many spaces on the map also have distinctive terrain features, like forests or mountains, which affects the ratings of units in those spaces.
Invasion: America is intended as a four player game; one player is the defender and controls the forces of the United States and Canada (Mexico and Central America is American-occupied territory). The other three players are the invaders; the European Socialist Coalition, the South American Union, and the Pan Asiatic League. Each turn of the game represented one month and the game lasted for 60 turns for a total of 5 years. The North American player wins if he still controls a portion of the continent by game's end. If the North American player loses, whichever of the invading players has the most territory is the winner. The result is that the invaders cooperate to an extent in attacking the North American player but are ultimately competing against each other.
Invasion: America was a popular game for SPI and led to a 1978 sequel; Objective Moscow in which it is the Soviet Union that is invaded.