Two Pipe Chess is a variant I entered in The Chess Variant Pages' 41-Square Contest, which asked for chess variants on boards with exactly 41 squares.   Two Pipe Chess gets its name from its initial arrangement of pieces, which looks somewhat like two tobacco pipes.
 
The pieces move just as in normal chess, except:
(1) there is no castling
(2) there are no bishops and pawns cannot promote to bishops
(3) pawns promote on the fifth rank.
 
The ZRF file contains two other variants:
(1) Two Pipe Extinction Chess: Extinction Chess on a Two Pipe Chess board.
(2) Two Pipe Non-Prise Chess: Non-Prise Chess on a Two Pipe Chess board.