Glossary
A Mao is a Knight who does not jump over obstacles.
A Mao performs the usual (1,2) knight displacement but decomposes it into first a 1-square rook move and then a 1-square bishop move. If the intermediary square is occupied, the Mao is obstructed, just like other non-leaping units may be.
In many ways, a Mao is not much different from a Knight. But on the other hand, a Mao can give discovered checks, or pin enemy units. Note that a Mao comeback uses different routes forward and backward.
The following triple (!!) check is legal:
(White Mao d4, Black Mao d3)
Here White is not in check. The triple check to the Black King is explained by an en-passant capture. Last moves were -1. c5xd6 ep+++ d7-d5 -2. Mf3xd4++.
Maos are part of the Chinese chessmen family of fairy men (invented by P. Seyfert in 1936) in which Queens, Rooks and Bishops are replaced by Leos, Paos and Vaos. This is outside (for now) our RA-centered scope. So let's rather admire a beautiful retro:
M. Caillaud 2nd Prize feenschach 1979
12+10. (Maos g1, e7) Both sides may castle. The game was played with Maos instead of Knights. (a) Where have the Bishops been captured? (b) Least number of moves by Mao b8?