Sky is played on a 10x10 board with 9 unusual, extremely awkward moving leapers. The only other piece used is the Rook, which comes on the board after promotion. All leapers can promote, and are arranged in 2 groups, both with a promotional line leading to the Rook. Each player begins with the 4 weakest leapers, and must quickly try to promote them, defending and attacking along the way! Don't get caught with your hand on your Rook while getting mated by your enemies Antelope's! :)
There are no pawns in Sky! Promotion zone is final 3 ranks (full details below). Leapers play surprisingly well together as an attacking force, and in combination with the Rook, they are often spectacular. I must admit, i was taken by surprise at how well the leapers played, giving the game an amazing amount of complexity, depth and richness of play. Gameplay can get pretty sharp and fast-paced.

Piece Descriptions:
Tripper: (3-3) leaper
Commuter: (4-4) leaper
Threeleaper : (0-3) leaper
Fourleaper: (0-4) leaper
Flamingo: (6-1) leaper
Antelope: (4-3) leaper
Lancer: (4-2) leaper
Root-fifty leaper: (7-1), (5-5) leaper
Fiveleaper: (0-5), (4-3) leaper
Rook: standard rook
King: standard king

Promotional Lines:
There are 2 promotional lines leading to Rook.
1. Tripper -> Threeleaper -> Flamingo -> Lancer -> Fiveleaper -> Rook
2. Commuter -> Fourleaper -> Antelope -> Root-fifty leaper -> Fiveleaper -> Rook

Opening Setup:
Each player starts with 7 Trippers, 4 Commuters, 2 Threeleapers and 2 Fourleapers.

Promotion Zone:
White = 8th 9th 10th rank, Black = 1st 2nd 3rd rank.
Any move that ends with a piece standing in promotion zone allows that piece to promote if desired (except Rook which does not promote)

Checkmate, stalemate or reducing enemy to lone king win the game.