Can a retrieved bishop rejoin the game so a player has two white space bishops? This bishop was all I had taken so I got it back after the pawn reached the other end.
Comments for Bishop brought back on Wrong Colour square
Yes Jane it's perfectly legal although maybe not a good policy. Two Bishops on the same color complex would be weaker than a traditional Bishop pair where each would cover different colored squares, thereby making them as a pair, much more powerful. Under-promotion, i.e. promoting to a Bishop, Knight or Rook rather than a Queen usually only takes place when promoting to a weaker piece is instrumental in your immediate plans, maybe necessary for checkmate or something. As the Queen can move like a Rook or a Bishop you only really see a pawn promoted to either of these when they a delivering checkmate on that move, some people think it's cuter to do it that way. Most of the time under-promotion features promotion to a Knight as this piece can control squares that a Queen cannot and this phenomenon can be part of a decisive variation to maybe win the game. But to reiterate, the answer to your question is it is legal to promote to a Bishop even if you end up with two Bishops on the same color squares.