Move Validation/Preview

Hi there,
I am just getting started on the Vassal docs, I see so much potential!

One question though, I didn’t find much (I confess I have just skimmed the doc) in the sense of support for move validation as in, enforcing game rules. For example, say I am coding a chess game, I would like to enforce that a pawn cannot move an arbitrary number of cells forward, and could not backtrack.

If this is not supported by the standard configuration, would it be possible to support by writing a Java extension? If so, are there any examples you could point me to?

Another feature would like to implement is displaying valid potential moves on hover, as an aid to users learning the game. Possible? Examples?


PS: I found a “chess’n’checkers” game in the module repo but it didn’t do any validation at all.