Classic
Sol (orange) moves first. Move one square diagonally forward on the dark squares. Jump an adjacent opponent to capture it.
Captures are mandatory. When another jump is available, continue with the same piece. You may choose any available capture; you don’t have to choose the longest chain.
Reach the far row to become a king, marked with a crown. Kings move and jump diagonally in either direction, one step or jump at a time. Crowning ends your turn, including a capture chain.
Win by capturing every opposing piece or leaving the other side with no legal move. A draw is automatic after three repetitions, or 40 turns each without a capture or an uncrowned piece advancing.
American / English checkers rules ↗Space Mode
Wormholes: Each new game connects two random dark squares, one on each middle row. After each round (once Sol and Luna both finish their turns), the wormholes relocate to two new empty dark squares anywhere on the board. They stay put during capture chains. Relocating wormholes never move or capture pieces. Undo restores their previous locations. Land on either to teleport if the exit is empty after your move. An occupied exit leaves you at the entrance. Each step teleports at most once. Continue any capture chain from your exit square; crowning is checked at your final square.
Thruster boost: Each side gets three boosts. Arm your thrusters to hop diagonally over one adjacent friendly piece into the empty square immediately beyond it. That piece stays on the board. Ordinary pieces boost forward; kings may boost in either direction. Each boost costs one charge and ends your turn, including after a wormhole jump or crowning.
Captures take priority. You cannot boost instead of a required capture or during a capture chain. A charge is spent only when you complete a boost; canceling is free. All other Classic rules apply.
Ranked play
Sign in with your Riftline account to play. Games against the computer count toward separate Classic and Space Mode leaderboards: a win earns 3 points, a draw earns 1, and a loss earns 0. Ties are ordered by wins, then fewer completed games, then player name. The leaderboard is public, with no login needed to view it. Your name is shared with Orbitfall and appears on the leaderboard; your email stays private.
Ranked moves and results are saved by the server. Refresh to resume an unfinished ranked game. Using Undo changes the current game to practice, and a completed ranked result cannot be undone. Same-device 2-player games are always practice. Practice games earn no points. Ranked games draw after 500 turns.
Controls
Click or tap a piece, then a highlighted destination. With a keyboard, use the arrow keys to navigate and Enter or Space to select. Escape clears your selection. Undo takes back your last turn and the computer’s reply.