Board Game Arena

Is there scope to include an undo button?

No; building an undo system really has to be something that's done from the start. I can see ways to add undo haphazardly, so some actions can be undone, but I feel the inconsistency would make the game so much more confusing. Players without deep technical knowledge of the code which runs the game won't be able to understand or predict why something could be undone, but not something else.

As always, I am happy to point people at the code and welcome them to volunteer their time to make changes: https://github.com/elaskavaia/bga-eminentdomain