--- /dev/null
+p.boxed
+ | Pieces can fusion and also be split under certain circumstances.
+
+p Fusion Chess is played like FIDE Chess with the following exceptions:
+
+h3 Fusion
+
+p.
+ A non-royal simple piece (Knight, Bishop, or Rook) may combine with
+ another simple piece on the same side (including a King) by moving
+ onto its square.
+
+p The combined piece moves as either of the two pieces just combined:
+ul
+ li King + Bishop = Pontiff
+ li King + Rook = Dragon King
+ li King + Knight = Cavalier King
+ li Bishop + Rook = Queen
+ li Bishop + Knight = Paladin
+ li Rook + Knight = Marshall
+
+p A piece may not combine with
+ul
+ li another piece of the same type,
+ li a piece belonging to the opponent,
+ li a compound piece.
+
+p.
+ A King may not move to combine any piece, though other another
+ piece may move to combine with its King.
+
+figure.diagram-container
+ .diagram.diag12
+ | fen:r1bqkbnr/pp1ppppp/2n5/2p5/4P3/5N2/PPPPBPPP/RNBQK2R:
+ .diagram.diag22
+ | fen:r1bqkbm1/pp1ppppp/2n5/2p5/4P3/5D2/PPPP1PPP/RNBQK2R:
+ figcaption Before and after moves BxNf3 and RxNg8.
+
+h3 Fission
+
+p.
+ An unattacked compound piece may split by moving one
+ of its components, under its own powers of movement, to an empty square.
+ul
+ li A Rook which separates from a piece must move away as a Rook moves.
+ li A Bishop which separates from a piece must move away as a Bishop moves.
+ li A Knight which separates from a piece must move away as a Knight moves.
+ li A King which separates from a piece must move away as a King moves.
+p The compound piece is replaced by the component which doesn't move away.
+
+h3 Other details
+
+p Any piece that has participated in fission or fusion may no longer castle.
+
+p Pawns may promote to Rook, Bishop, or Knight only.
+
+p.
+ The object is to checkmate your opponent's current royal piece, which may
+ be a King, Pontiff, Dragon King, or Cavalier King.
+
+p.
+ No royal piece may move through check when moving more than one space.
+ For the Cavalier King, the Knight move is understood as beginning
+ orthogonally and turning diagonally or vice versa. If both spaces
+ it might pass over to reach a square are checked, it cannot move there.
+ However, this does not limit its ability to check or attack a piece.
+
+figure.diagram-container
+ .diagram
+ | fen:r3br2/c2p4/1pd2pqp/p1B5/1D1P1QP1/8/PPP1P2P/2RG2N1 c8:
+
+p.
+ On the diagram above, the Cavalier King only non-splitting move as a Knight
+ is to c8. Indeed, a6 and b6 are under attack. b8 as well, but not b7.
+
+h3 More information
+
+p
+ | See the
+ a(href="https://www.chessvariants.com/other.dir/fusion.html")
+ | chessvariants page
+ | .
+
+p Inventor: Fergus Duniho (1999)