TODO

   1 # Enhancements:
   2 Desktop notifications
   3 Do not remove other challenges when one is accepted?
   4
   5 # New variants
   6 Finish first https://www.chessvariants.com/mvopponent.dir/dynamo.html
   7 https://echekk.fr/spip.php?page=article&id_article=599
   8
   9 Monster, Horde, Colorbound
  10 https://www.chessvariants.com/d.betza/chessvar/dan/colclob.html
  11 https://lichess.org/analysis/horde#0
  12 https://greenchess.net/rules.php?v=monster
  13 https://en.wikipedia.org/wiki/Monster_chess
  14 https://en.wikipedia.org/wiki/Grotesque_(chess) (fun)
  15
  16 Maxima, Interweave, Roccoco
  17 https://www.chessvariants.com/other.dir/rococo.html
  18 https://www.chessvariants.com/dpieces.dir/maxima/maxima.html
  19 https://www.chessvariants.com/other.dir/interweave.html
  20
  21 Take(a)n(d)make : if capture a piece, take its power for the last of the turn and make a move like it.
  22 If a pawn taken: direction of the capturer, can capture enemy.
  23 http://www.strategems.net/sections/fairy_defs.html
  24 Having captured, a unit must immediately, as part of its move, play a non-capturing move, using ONLY the powers of movement of the captured unit from the capture-square. If no such move is available, the capture is illegal. Promotion by capture occurs only when a pawn arrives on the promotion rank as the result of a Take & Make move. Checks are as in normal chess: after the notional capture of the checked King, the checking unit does not move away from the King’s square.
  25
  26 Chakart :)
  27
  28 https://en.wikipedia.org/wiki/Fairy_chess_piece