ZugzwangedBuild or import your repertoire
Add the moves you want to play, or import a Lichess Study you already use.
Chess opening training built around your games
Build your repertoire. Learn from your games.
Choose the lines you want to play, practise them with spaced repetition, and see exactly where your Chess.com or Lichess games left your book.
Prioritised by what players at your rating actually face — not by someone else's course.
Use it in your browser or on iPhone via the App Store.
How it works
Build it. Practise it. Improve it.
Practise the moves that matter
Train your own lines with spaced repetition, giving common opponent replies more attention than rare sidelines.
Learn from your games
Add your Chess.com or Lichess username to find repertoire gaps and tactical mistakes. No password or account access required.
Repertoire builder
Build the book you actually want to play.
Add lines move by move or import an existing Lichess Study. Every opponent reply shows how often you meet it at your rating and time control, so you can cover and train the lines that matter — and leave rare sidelines as reference.
Spaced repetition
Keep the repertoire ready.
Train your own lines with spaced repetition. Common replies receive more attention, rare sidelines receive less, and you can always ignore the schedule and drill an entire book when you want to prepare intensively.
Your games
See exactly where the game left your book.
Add your Chess.com or Lichess username and Zugzwanged compares your games with your repertoire. When a game leaves the book, open that exact position in the analysis board, inspect the alternatives, and decide whether the repertoire needs to change.
Tactics
A complete tactics trainer — built in.
Solve rated puzzles, train custom sets by theme and difficulty, repeat failed positions, or work through Woodpecker-style cycles. Zugzwanged can also mine suitable tactical mistakes from your own games, giving you positions drawn directly from your play.
Insights
See what needs attention.
Follow your puzzle rating, compare themes against your own level, and revisit positions you failed. Zugzwanged shows progress and weak spots without adding leagues, levels, or artificial rewards.
Who it's for
Built for players who manage their own improvement.
Zugzwanged is for players who want to build or import their own repertoire, review what happened in their real games, and train with purpose. It does not sell opening courses or choose a fixed repertoire for you.
Build or import your own repertoireReview positions from your real gamesTrain openings and tactics with purpose
Try your first line now.
Try the real Explorer without an account. Sign up only when you want to save your repertoire and progress. Questions? Write us at [email protected]