Basically you have 3 discs in your color and three sets four concentric rings nested in each other.
You place one piece at a time, either on a space you've already played (trying to claim it with a majority of your color) or on a space adjacent to one you've played (to increase your play options).
You go until everyone is out of pieces or no one can make a move, whichever comes first.
You win by having the most spaces where your color is the majority. You can get a majority by having one of your pieces, with no one elses; two of your pieces and either one of another color or two of two different colors; or having three or four of your color on a space.
Fun game.