Rules:
Basic gameplay: Reduction is played on a square board of some size which the players can choose (side length between 10 and 20). Each space of this board is either empty or full; the board starts out with each space randomly empty or full. In Reduction, players make changes to the board. There are three types of change; each of these types affects only a 2x2 region of the board and can be done by clicking near the center intersection of that 2x2 region. If you can make a change on a 2x2 region, that region's center intersection will be green; otherwise, its center intersection will be red.
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Take an entirely empty 2x2 region and make it entirely full.
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Take an entirely full 2x2 region and make it entirely empty.
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Take a 2x2 region with only two spaces filled and with those two spaces separated by a diagonal (rather than one being directly above or to the left of the other), and to flip all the spaces in that 2x2 region, resulting in that region still having two diagonally separared full spaces but with those spaces being the other two spaces in the region.
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