Medium International checkers
Medium International checkers is the default opponent on International checkers. Same 10×10 start, flying kings, and strict longest capture.
Easy searches one ply. Hard searches five. The rules and board never change.
International rules at Medium strength
Remove every opposing piece, or leave the other side with no legal move. The game uses the standard 10×10 International draughts start: twenty men each on fifty dark squares, white to move first.
- Men step one square diagonally forward on quiet moves; captures may run forward or backward.
- When jumps are available you must capture; if several lines exist, you must take one that captures the maximum number of enemy pieces (longest capture).
- Kings fly along open diagonals and may land on any empty square beyond a taken piece.
- A man promotes to a king only when the move ends on the far rank. A capture that passes that rank and continues leaves the piece a man; it does not fly on that turn.
What the Medium International opponent searches
The Medium opponent searches with alpha-beta depth about 3 on the same 10×10 rules.
The evaluation weights men, kings, and mobility with mandatory longest capture and flying kings; only search depth changes between Easy, Medium, and Hard.
It respects obvious longest-capture lines but will not calculate every quiet king endgame five moves deep.
Steady International play at Medium
Sketch the whole capture tree
Before you touch a piece, list every legal longest line — including king landings beyond the first victim. Medium will punish a one-move miss in a forced sequence.
Tempo with flying kings
After the opening, open diagonals favor kings. Trade men when ahead, but keep kings active on long diagonals Medium cannot shut down in one reply.
Promotion at the end of the move
A man becomes a king only if the capture ends on the far rank. If the chain passes that rank and continues, the piece stays a man and cannot fly. A flying continuation after only visiting the king row is illegal.
International checkers difficulty levels compared
| Level | Best for | Search | Typical gap | Practice focus |
|---|---|---|---|---|
| Easy | First games on the 10×10 board | alpha-beta depth ≈ 1 | Misses longest-capture forks two plies away | Count every piece in a forced jump before you tap |
| Medium (this page) | Regular International draughts practice | alpha-beta depth ≈ 3 | Finds short tactical shots; weaker on quiet king endgames | Use backward man jumps to open flying king lines |
| Hard | Longer tactical lines on 50 squares | alpha-beta depth ≈ 5 | Still fixed depth — not FMJD-level International play | Plan long capture chains — a man crowns only if the chain ends on the far rank |
Need a refresher on the basics? Read the complete International Checkers guide and rules on Checkerso for 10×10 board rules, mandatory longest capture sequences, and flying kings.
Frequently asked questions
How is Medium International different from Easy?
Both use the same International rules engine. Medium runs alpha-beta depth about 3 instead of depth about 1.
Is Medium the same as Pool or American Medium?
No. Those modes use an 8×8 board without mandatory longest capture. Medium International is its own ruleset and its own stats bucket.
Do I need to memorize opening theory?
Not for this page. Medium is for practicing tactics — longest capture, flying kings, and backward jumps — on the standard 10×10 start.