p.boxed
  | Choose squares for new pieces to appear when the initial ones are moved.
  | One extra knight (first move), and one extra bishop (second move).

p.
  Everything is the same as in orthodox rules, except that new pieces appear
  at initially selected locations: a knight and a bishop.

p.
  The first move of the game selects the square for the knight
  (just click on a square on the first rank),
  and the second move picks the square for the bishop.
  When an "augmented piece" moves, the extra piece enter into play on the
  initial square.

figure.diagram-container
  .diagram
    | fen:rnaqkbor/pppppppp/8/8/8/8/PPPPPPPP/RMBQKCNR:
  figcaption Augmented pieces on b1, f1, c8 and g8.

p.
  Castling is always possible. If both pieces involved are augmented,
  then two extra pieces appear at the end of the move.

figure.diagram-container
  .diagram.diag12
    | fen:rm1qkbor/ppp2ppp/4b3/3pp3/8/5NP1/PPPPPPBP/RNBQJ2V:
  .diagram.diag22
    | fen:rm1qkbor/ppp2ppp/4b3/3pp3/8/5NP1/PPPPPPBP/RNBQNRKB:
  figcaption Before and after 0-0.

h3 More information

p
  | The variant idea was suggested recently, and corresponds to 
  a(href="https://musketeerchess.net/home/index.html")
    | Musketeer Chess
  | , using non-fairy pieces.

p Inventor: Zied Haddad (2020)