Ponderchess / Special moves
Recognize a repeating position and a possible draw claim.
Count positions, not just repeated moves.
The same player must be on move each time.
Available moves, including castling and en passant, must match.
Play the guided film, or select a scene to pause and study its position.
Rule
Perpetual check in 3D
Black is a rook up. But White's queen can check the king again and again.
Rebuild the sequence yourself. The board responds to each move, and hints are available.
Click or drag to move · Arrow keys + Enter to play
Your turn · white to play
Select a piece, then its destination. Switch to 2D for a clear overhead view or rotate the 3D board to explore the position.
A rook down, White saves the game by checking forever until the position repeats three times.
Idea 01
Idea 02
Idea 03
A rook down, White saves the game by checking forever until the position repeats three times.
Keyboard: Space pauses, the arrow keys step. Gold arrows are White's moves, violet are Black's, red rays are threats, green shows support, blue shows plans.
Make the idea yours
No timer. No score. Just a moment to check your understanding.
