-p.boxed TODO
+p.boxed
+ | Pieces turn around the board, they cannot go in the middle.
+
+p.
+ Each side has only a king, two rooks, one bishop and two pawns.
+ Pieces can never enter the central area.
+ Pawns can only move "clockwise", acording to the image below: they move
+ and capture forward straight and diagonally in the arrow direction.
+
+figure
+ img.img-center(src="/variants/Rollerball/rollerball_directions.gif")
+ figcaption.text-center.
+ Main directions on the board.
+ The squares where direction changes are enlighted with white arrows.
+
+p.
+ When a pawn reaches the starting square of an enemy pawn, it promotes
+ into a bishop or rook.
+
+p.
+ Rooks and bishop move as usual, but are restricted to one square only when
+ moving counter-clockwise.
+ Moreover, they are allowed one rebound in certain circumstances:
+ul
+ li a bishop rebounds on the first wall met,
+ li a rook rebounds (at 90 degrees) if it reaches a corner.
+
+figure
+ img.img-center(src="/variants/Rollerball/rook_example.gif")
+ figcaption.text-center Some rook movements.
+
+p.
+ The king moves as in orthodox chess.
+ The goal is either to bring your king on the initial square of the
+ opponent's king, or to checkmate him.
+
+h3 More information
+
+p
+ | See the
+ a(href="http://history.chess.free.fr/rollerball.htm") author's presentation
+ | , and the
+ a(href="https://www.chessvariants.com/40.dir/rollerball/index.html")
+ | chessvariants page
+ | .
+
+p Inventor: Jean-Louis Cazaux (1998)