Undo

[King Hrothbeort]

Some games have undo buttons, some don't
I hate to lose because I clicked the wrong button; I don't even like to win because my opponent clicked the wrong button.
Therefore I am in favor of undo buttons, as long as they only undo the active player's move that other players have yet to respond to and no new information has been revealed e.g. drawing face down cards.

[Shobu]

Seems the undo functionality is far from being simple to implement.
It's a good feature, but i can do without it if this means more game available here

[nccc]

Do u know different games are probably designed/implemented by different devs? So u have to ask for the function separately. And use BUGS page plz.

[voriki]

Indeed like nccc said, it's a separate function for each game.

For most games this is also a big thing as most actions would reveal hidden information(drawing the next card, etc...), you cannot unhide this knowledge, hence why games where this is applicable do not have an undo button, just exactly for that reason.