The ancient mill game gets a bluff: your three-in-a-row only captures if the men share a hidden colour.
Place and then move your nine men to form mills. A mill only triggers a capture if all three men in the line share the same secret colour. Reduce your opponent below three men, or leave them with no legal move, to win.
Nine men's morris is old enough to predate the Roman Empire's decline, and has carried a dozen names — mill, merels, merrills, marelles, ninepenny marl. Place nine men, then move them, and completing a line of three lets you take an enemy piece.
The original rule is that each man has a secret colour, and a mill only captures if all three men in the line share it.
Morris is a solved game that draws with perfect play, and it is solved because a mill is a mill — the board tells you everything. Hiding a property of your own pieces means you can form a line and learn only then whether it was worth forming, which is not a variation on the strategy so much as a different game wearing its board.
Morris Mirage layers hidden-colour deduction over the classic nine men's morris mill game. It is an original free browser game built in-house for PlayPendium.