Mirror Random

Chess960 with the constraints removed. The back rank is shuffled at random and both players get the same arrangement, but nothing governs bishop colour or where the king stands, and castling follows the position. Two same-coloured bishops or a king in the corner are ordinary here. No theory has ever been written about any of it.

Start a free game of Mirror Random in the browser while you read; no sign-up.

The rules

The back rank is shuffled at random and both players receive the same arrangement. Unlike Chess960 there are no constraints on bishop colour or king placement, and castling rules follow the position.

Why it is worth playing

Mirror Random is Chess960 with the training wheels off. Because there are no constraints, positions can be genuinely strange (two same-coloured bishops, a king in the corner) and no theory has ever been written about any of them.

Four plans that win games

Find the weak pawn first

In an unconstrained random position there is nearly always a pawn defended only once. Locate it before you develop.

Identify your worst piece

Every random arrangement has one badly placed piece. Your opening plan is to fix it.

Symmetry means tempo matters

Since both sides have the same setup, the player who finds the best plan first has the only advantage available.

Reassess castling every move

Depending on the arrangement, castling may be excellent, illegal or actively bad.

Mistakes that lose games

What it teaches you about standard chess

Principles versus memory

Like Chess960 but without the constraints that keep positions sane. If your principles are real they will work here; if they were rules of thumb attached to familiar positions, they will not.

Mirror Random does what every good variant does: it removes part of chess so that what is left gets your full attention, and the habit comes back with you to the standard game. The full argument, and which variant trains what, is in the coach's guide to variants.

Who it suits

Chess960 players who want more chaos, and anyone testing whether their principles are real.

You can play it right now on any device, in a browser, against a full engine, with no download and no account. If you have never tried a variant before, give it three games rather than one: the first is spent learning the rules, and the second is where it starts being chess.

Common questions

What are the rules of Mirror Random?

The back rank is shuffled at random and both players receive the same arrangement. Unlike Chess960 there are no constraints on bishop colour or king placement, and castling rules follow the position.

Is Mirror Random hard to learn?

The rules take about two minutes. Chess960 players who want more chaos, and anyone testing whether their principles are real.

What is the best strategy in Mirror Random?

Find the weak pawn first. In an unconstrained random position there is nearly always a pawn defended only once. Locate it before you develop.

Where can I play Mirror Random free?

Grandmaster Gains has Mirror Random playable in the browser against a full engine, free and with no sign-up, alongside nineteen other variants.

Will playing Mirror Random improve my normal chess?

Principles versus memory. Like Chess960 but without the constraints that keep positions sane. If your principles are real they will work here; if they were rules of thumb attached to familiar positions, they will not.

What is the biggest mistake beginners make in Mirror Random?

Do not assume standard weaknesses. f2 and f7 may be well defended in this arrangement, and some other square may not be.

More variants

• Double Random: Both back ranks randomised independently, so the armies do not match.
• Peasants' Revolt: One side has a king and eight pawns; the other has a king, four knights and a pawn.
• Light Brigade: One side gets a queen and pawns; the other gets minor pieces and pawns.
• Standard Chess: The original, and still the deepest game on the board.