Mate in 3 in chess
Force mate in three moves against every defense. This is usually the depth where spotting a pattern stops being enough and you have to calculate each line.
A mate in 3 puzzle asks you to force checkmate in three of your own moves, whatever legal defense the opponent chooses. Some defenses allow mate sooner, but none can delay it past your third move.
What makes three harder than two
In a mate in two you check one layer of defenses. In a mate in three the defender moves twice, so each reply to your first move opens new branches of its own. The skill being trained is discipline: holding several lines in your head and finishing each one instead of stopping at the first that looks convincing.
Mate-in-three puzzles taken from real games almost always start with a check, often a sacrifice. In a sample of about 1,000 of the trainer's mate-in-three puzzles, 97% opened with a check, and Lichess tags almost half of them as sacrifices. A quiet move, a first move that gives no check but takes away escape squares or leaves the defender in zugzwang, is rare in game puzzles. It is the usual start in composed problems, where composers avoid a checking first move. So try the checks first, and look for a quiet move when none of them works.
Work backwards. Picture the final mating position first, then ask what has to be true for it: which squares must be covered and which defender must be gone. The answer often points to the first move.
A working method
- List all forcing moves: checks, captures, and threats of mate.
- For each, list all the defender's legal replies, not only the one that looks best.
- Prune fast: drop a candidate as soon as one reply lets the king escape to a square you cannot cover in time.
- When every branch of a candidate move ends in mate, you have the solution. If one branch is unresolved, you do not.
- Only then play the move.
Turn misses into study
When you fail a mate in three, open the position on the analysis board and play out the defense you missed, instead of only reading the answer. Seeing why your line fails helps the pattern stick.
Practice the mate in 3
Reading about a pattern is not the same as spotting it under time pressure. The free chess puzzles trainer serves rated positions from real games and adjusts to your level as you solve. When you get one wrong, press Analyze once the puzzle is over to open it on the analysis board and see what you missed.
Related tactics
Mate in 2
Force mate in two moves. It is pure calculation training, and you can always prove the answer: every defense runs into mate.
Smothered mate
In one of the prettiest mates in chess, a knight checks a king that cannot move because its own pieces fill every square around it.
Double check
Two checks at the same time, and the king has to move. No other answer is legal.
Frequently asked questions
How do I calculate a mate in 3?
Work backwards from a mating picture, list all forcing first moves (checks first, since most solutions start with one), and for each one check every legal defense, not only the most natural. Checking every reply matters more than seeing far ahead.
Are mate in 3 puzzles good training?
They are excellent for calculation and for the habit of checking all defensive replies. For general improvement, mix them with ordinary tactical puzzles that win material. About two in three Lichess puzzles, all taken from real games, end without a mate.