Polyominoes are a generalization of dominoes and they give rise to many curious problems, from tilings of dissected chessboards to tetris. They're simple objects, but even the simplest of questions can be hard to answer, and require cunning techniques and approaches.
For example: you can't (of course!) cover a chessboard with straight triominoes (the one on the right in the link). What if you remove a single square from the board -- can you find a way to do it then? There are some similar puzzles here; if you're in a more serious mood, there are plenty of unsolved problems [PDF] in this field too.
This session will no doubt be a bit "lighter" than usual, with puzzles and games taking centre stage. Still, we'll be touching on mathematical topics that come up in more serious contexts too.
As always, all are welcome, whether it's your first time or not. No preparation is needed and we don't expect you to have any specific knowledge about maths, just a willingness to explore, experiment and discuss.