ILLEGAL MOVEMENT

There are a couple of situations that can result in movement not being allowed:

Each tower and each empty space can hold up to 6 wizards. If a move would exceed that limit, you cannot make that move.

If a move would put towers atop Ravenskeep, you cannot make that move.

Note: If you [accidentally] lift a tower whose move would place it atop Ravenskeep, your turn ends immediately without moving the tower you lifted (fill your hand to 3 cards as usual).