Grab yourself some steel washers from the hardware store and a sheet of magnetic paper (like for making fridge magnets). Add these nice stacking game pieces, and you've got a kit that lets you create any sort of abstract strategy board game you can imagine!

The peg at the bottom of the piece fits nicely into the hole in the washer so the piece stay put.

The STL makes these heavy and dense so they feel nice in the hand.

You can also stack them on each other for games that need that. You can print in white PLA and then use acrylic to paint them, or just print in colorful filaments.

You could also make little models that fit into the holes at the top of the peg to denote special units/promotions etc.