Bukkit

A player was having a game of chess, playing black and was denied the ability to make what 3 of us unanimously believe were legitimate moves.

http://imgur.com/nqizW2l

I'll try to explain it sensibly! The black queen's (wither skeleton) knight moved to queen's bishop (witch) 3
The white bishop took the black knight and placed the black king (enderman) in check.
The player then wasn't allowed to move either the queen or the bishop into the path of check and had to take the white bishop with the queen's knight pawn (cave spider). Both of those should have been legitimate moves yes?

It certainly looks a bit weird, I agree. I'll try to reproduce the problem and get back to you.

OK... tried to reproduce it, and I can't :(

Using the bishop or queen to block here is definitely a valid move and I was allowed to do it in a test game against myself. Since I can't see your whole board, I can't tell what other moves have been made, but that shouldn't make a difference.

If you still have your saved game file (in plugins/ChessCraft/data/games), I'd quite like to see it...