Caissly · an encyclopedia

An encyclopedia, worthy of the game.

For centuries chess belonged to books. Then it belonged to engines. Caissly is the third chapter — chess, written in our age, for those who still wish to read.

Openings
3,161
Annotated games
105
Player profiles
24
Essays
4
Variants
6
Glossary terms
46
Try the explorer → ECO B90
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Black rook
Black knight
Black bishop
Black queen
Black king
Black bishop
Black rook
Black pawn
Black pawn
Black pawn
Black pawn
Black pawn
Black pawn
Black pawn
Black knight
White knight
White pawn
White knight
White pawn
White pawn
White pawn
White pawn
White pawn
White pawn
White rook
White bishop
White queen
White king
White bishop
White rook
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6
Click to open this position in the interactive explorer.
Issue · Long-form

From the editor's desk

All essays →
Issue №2 · Lead Feature

Gukesh and the End of European Hegemony

At 18, D. Gukesh became the youngest world chess champion in history. The Indian generation behind him is not an accident — it is the end of an order.

Browse the library

Six ways to open the book.

Player biographies

The faces of the book.

All players →
Magnus Carlsen
Magnus Carlsen
🇳🇴 Norway · peak 2882
Garry Kasparov
Garry Kasparov
🇷🇺 Russia · peak 2851
Anatoly Karpov
Anatoly Karpov
🇷🇺 Russia · peak 2780
Bobby Fischer
Bobby Fischer
🇺🇸 United States · peak 2785
José Raúl Capablanca
José Raúl Capablanca
🇨🇺 Cuba · peak 2725
Mikhail Tal
Mikhail Tal
🇱🇻 Latvia · peak 2705
Emanuel Lasker
Emanuel Lasker
🇩🇪 Germany · peak 2720
Mikhail Botvinnik
Mikhail Botvinnik
🇷🇺 Soviet Union · peak 2730
Annotated chess history

Games that made the book.

All games →
Side rooms

Beyond the main board.

All variants →
Bughouse
Bughouse is two-against-two chess. Each pair plays one board with reversed colours. When you capture a piece, it goes onto your partner's side — they can drop it onto their board as a move. The result is fast, noisy, and unlike any single-board chess in the world.
2v2
Atomic Chess
Atomic chess adds a single brutal rule: any capture causes an explosion that removes the captured piece, the capturing piece, and any non-pawn piece on the eight surrounding squares. Pawns survive explosions. The king cannot capture (because it would die). Win by exploding the enemy king or by mate.
1v1
Chess 960
Chess 960 randomises the back-rank pieces before move 1. Bishops always sit on opposite-colour squares; the king always sits between the rooks. After that, every line of theory you know is irrelevant.
1v1 · FIDE-recognised
Antichess
Antichess inverts the win condition. You win by losing all your pieces or by being stalemated. Captures are forced — if any capture is legal you must play one — and the king is not royal: it can be captured, has no check, and may be left in check. The variant turns standard chess intuition inside out.
1v1
King of the Hill
King of the Hill is standard chess with one additional winning condition. If your king reaches d4, d5, e4, or e5 — and is not in check on that square — you win immediately. The four central squares act as a target alongside the enemy king.
1v1
Crazyhouse
Crazyhouse is one-on-one chess where captured pieces switch sides instead of leaving the board. When you take an opponent's piece, you can drop it back onto any empty square as a future move. The result is bughouse's tactical density compressed onto a single board.
1v1
Welcome to Caissly

The library is open.
Pick a door.

Begin with the openings tree — the interactive explorer covers every line in the encyclopedia. Or read an essay over coffee. Or look up a player whose games you've always meant to study.