Cathedral
25 years ago, I wrote a Cathedral game board in Flash that you can play over the network with someone. Thanks to Ruffle, it now lives again!
Play at eco.3e.org/cathedral - you and your opponent should enter the same names for each other in order to be connected.
This is just a game board - it does not enforce any rules. That's up to you. The 'end turn' button lets your opponent know you're done by playing a sound.
