Strategies
From Polarity
A definition of strategy and strategic play: A strategy is a long term plan of action designed to achieve a particular goal. A strategic move is one which influences an opponent's choice in some way. Distinct from tactics in that it is not concerned with the individual means to achieve a specific goal but rather in achieving the objectives of the game.
General Magnet Info
Technical Information
The magnets used in Polarity are thin solenoids. The magnetic field comes out of the center of the magnet and bubbles around the outside to come back in the center on the other side. It is shaped like a doughnut.
In the center of the disc (the doughnut hole) the field is very strong and convergent. Disc centers facing each other this way will either strongly attract or strongly repel.
the field around the side of the disc is weak and divergent and won't cause too much force.
When you place a leaner you are really pointing the bottom center of your leaner at the bottom of the foundation. These have a repulsive force. When this force balances the gravity pulling down on the leaner, it will hover as it should.
If the leaner gets too vertical, the bottom center of the leaner is now pointing at the top of the foundation. This creates an attractive force and will probably suck the foundation up. This is why playing on towers of 2 is fairly easy, because the center of the top magnet is higher and the leaner wont point at it. Playing on very high towers is hard because you are using mostly the divergent side field for support. They must stand almost vertical to minimize the pull of gravity.
Useful Information
You can see why leaners add so much instability to the board. Rather than the strong part of their field pointing straight up (as foundations and towers do), leaners point their field somewhat across the board surface too. The more vertical the standing piece, the more the field points across the board.
Sometimes you can imaging a straight line going thru the center of all the discs to try and get an idea of the magnetic field topography.