There are four bases in Chess, which are each placed at a corner of the board (on squares A1, An, ℵ0, and ℵ∝). Home base, also known as home plate, is shaped like a pentagon, while all the rest are shaped like rectangles. A piece that rounds all four bases earns a point. Each player can expand upon any base that they find, although which expansions are available depends on their current tech level. The only way to neutralize a player's base is by dousing it with acid.