01 / SUDOKUSudoku
9×9 & mini puzzles
Eleven connected steps, mini and classic grids, new-grid generation and full answers.
Preflight Play · SUDOKU / XIANGQI / GO
Learn the rules. Find your next move.
Start with a lesson, explore a puzzle, or invite a friend. Three games, at your pace.
✓ No account needed✓ Play & learn
01 / SUDOKU
02 / XIANGQIXiangqi
Lessons & endgames
Seventeen learning steps, 76 classical positions, practical endings, master-game replays and invite-only rooms.
03 / GOGo
Capture lessons & 9×9
Thirteen learning steps, Xuanxuan Qijing and Guanzi Pu studies, Danghu replays and 9/13/19 room play.
LEARN BY DOING
Xiangqi / first lessonLearn by doing
01 / THE HORSE
An L-shaped move with a blocking rule.
The horse moves two intersections along one axis and one along the other. Unlike a chess knight, it is blocked when the first straight step—the horse’s leg—is occupied by either side. Select the horse in our lesson, compare the highlighted destinations and try a move.
- Select the red horse.
- Compare legal and blocked directions.
- Complete the move; Retry restores this lesson.
Try a move, retry and compare. Learn one piece at a time.
Rules with worked examples
Xiangqi / FIELD NOTES
Xiangqi rules for beginners: horse, elephant and cannon
Learn three easily confused Chinese chess moves with coordinate examples, then test them in the interactive lessons.
Read the story ↗Go / FIELD NOTES
Go for beginners: liberties, atari and capturing stones
A practical way to read connected stones, identify the last liberty and avoid confusing a temporary escape with life.
Read the story ↗Sudoku / FIELD NOTES
How to solve Sudoku: candidates, naked singles and hidden singles
Learn why a digit belongs in a cell, how two types of singles differ, and how to use answers without losing the reasoning.
Read the story ↗BEYOND THE NEXT MOVE
All field notes ↗Go deeper: explain your next move
Xiangqi / FIELD NOTES
Xiangqi checkmate: count the escapes before you check
Work through three small positions to distinguish a check from mate, explain each chariot’s job and see how one horse changes the answer.
Read the story ↗Sudoku / FIELD NOTES
Sudoku after singles: pairs and locked candidates, explained
Learn why candidate eliminations work, when a pair is valid and how a box can restrict a row. Includes counterexamples and a self-check.
Read the story ↗Go / FIELD NOTES
Your Go group is in atari: count, connect or capture?
Count shared liberties, compare an extension with a capture and learn why adding a stone may not improve safety. Worked coordinates and a self-check included.
Read the story ↗