Chess opening repertoire builder
Play your lines below and see, at your rating level, which replies you’ll actually face — and where your repertoire has holes. Free, no account needed; create one when you want to save it.
Your move = pick one; opponent move = add every reply you want to be ready for.
How it works
Choose White or Black and your rating band, then optionally import your recent games by username.
We pull the most-played replies from the Lichess players database at your level and flag the lines your repertoire doesn't answer yet.
Add your responses move by move, create a free account to save it, then drill the lines with spaced repetition.
Build your first two branches
On an empty repertoire, load the practice repertoire above. It contains a short White 1.e4 line and a different reply from Black. Loading it is disabled while you have existing moves.
- Select 1.e4 in the move tree. Find Black’s two replies: ...e5 and ...c5.
- Follow ...e5 2.Nf3 Nc6 3.Bc4, then return to 1.e4 and follow ...c5 2.Nf3.
- Select one branch and examine the available reply statistics for your chosen rating group. A missing statistic does not mean the move is illegal or bad.
Why keep ...c5 if I want to play an Italian Game?
Black chooses the reply to 1.e4. The Italian line requires ...e5 and ...Nc6; you need a separate response when Black chooses ...c5.
How deep should I extend this practice tree?
Add a reply you understand and can explain, then test it on the board. This example is a starting structure, not a recommendation that a fixed number of memorized moves is enough.
Are the sample moves imported from a real player?
No. This is a fictional practice tree. Use Import my games for your own history; distinguish those games from the general explorer statistics.
Frequently asked questions
Is the opening repertoire builder free?
Yes. You can build and explore as much as you like with no account. A free account includes your first saved repertoire with up to 20 lines and its training. Premium adds larger and additional repertoires. Your browser draft remains available if you exceed the free allowance.
Do I need an account to use it?
No. Everything runs in your browser and your work is kept locally. Create an account when you want to save it so you don't lose it across devices.
Where do the move statistics come from?
From the Lichess players database, filtered to your rating band and excluding bullet, plus the masters database — so you see what opponents at your level actually play.
Can I import my Chess.com or Lichess games?
Yes. Enter your username and we pull around 100 of your public games for the chosen colour and seed your repertoire from the openings you already play.
What is an opening repertoire?
A prepared set of moves for the openings you play: one chosen move for each of your turns, and an answer ready for every common reply your opponents make.
What happens when I create an account?
Your repertoire is saved to your account, where you can keep adding lines, drill them with spaced repetition, and check whether your real games followed your preparation.