StackWorks — Columns Chess Help & Rules

Columns Chess combines chess movement (including check) with Lasca-style stacking captures. Squares can hold a stack (a “column”) of pieces.

Rules Overview
Movement & Check
Stacks (Columns)
Captures & Remainders
Repetition & Ko
Using the Interface
Notation

Rules Overview

Movement (Chess)

Pieces move like chess: King, Queen, Rook, Bishop, Knight, Pawn.
Check rules apply: you may not make a move that leaves your king in check.
Castling and en passant exist when allowed by the current state.
Promotion happens on reaching the final rank (as in chess).

Stacks + Stacking Captures

Only the top piece of a stack determines who controls that square.
Captures remove only the top piece of the captured stack.
The captured top piece is inserted at the bottom of the capturing stack on the destination square.
If the captured stack had a remainder (more pieces underneath), the remainder is moved back to the capturer’s origin square.

Repetition & Draws (Chess-style) + Ko

Ko (immediate recapture ban): immediately after a capture, you may not make a move that recreates the exact position from before that capture.
Threefold repetition (claimable draw): if the same position occurs at least 3 times, the player to move may claim a draw.
Fivefold repetition (automatic draw): if the same position occurs at least 5 times, the game is drawn automatically.

Movement & Check

You move like chess. Legal destinations are highlighted after selecting a piece/stack.

        Check reminder: Even if a move is otherwise legal by movement, it
        is illegal if it leaves your king in check.
      

Stacks (Columns)

A square can contain a stack of pieces (bottom → top).
Only the top piece determines which player controls the square.
Hover a stacked square to open the Stack Inspector (right panel) and see the full column order.
A small “mini spine” preview is drawn for stacks on the board. It is shown inside the square on the right side, and stays on screen-right even when the board is flipped.

Captures & Remainders

A capture targets an occupied square.

What a capture does

Captures remove only the top piece of the captured stack.
That captured piece is inserted under the capturing stack on the destination square.
If the captured stack had more than one piece, the remaining pieces (the “remainder”) are moved back to the capturer’s origin square.
If the captured stack had exactly one piece, the origin square becomes empty.

Repetition & Ko

Columns Chess uses chess-style repetition draws (threefold claimable, fivefold automatic). This is about repeating the same position, not repeating the same moves.

A position counts as “the same” only if the same legal moves exist. In practice that means the same board (including stack order), the same player to move, and the same chess rights (castling + en passant availability).

The same player is to move.
The same pieces (type + color) are on the same squares, with the same stack order in each column.
The same legal moves exist — which means castling rights and en passant availability must match too.

Ko (immediate recapture ban)

Ko is checked only immediately after a capture.
A move is illegal if it would recreate the exact position that existed immediately before the last capture.
Ko is cleared as soon as a non-capture move is made.

Threefold repetition (claimable draw)

If the same position occurs at least 3 times, the player to move may claim a draw.

Fivefold repetition (automatic draw)

If the same position occurs at least 5 times, the game is a draw automatically (no claim needed).

Using the Interface

Click a piece/stack to select it, then click a highlighted target to move.
Hover stacked squares to open the Stack Inspector and see the full bottom → top order.
Layout (Options → Layout) switches between Panels (sidebars) and Menu (tap ☰ to open panel sections as dialogs).
Use the Start Page link in the top bar to return to the Start Page.

        Open Game Panel → Players to choose Human or
        Bot for White and Black. If you choose Bot, the second
        dropdown lets you choose a tier (Beginner / Intermediate /
        Advanced / Master).
      

Columns Chess can also use Stockfish for approximate position evaluation and first-pass move suggestions. Because Stockfish does not understand stacks directly, StackWorks treats that engine output as a helpful hint and lets the built-in Columns Chess search refine or replace the move when stack-aware tactics disagree.

Keyboard shortcuts

Shortcuts use Ctrl (Windows/Linux) or Cmd (macOS). Shortcuts are disabled while typing in a text field.

Undo: Ctrl/Cmd+Z
Redo: Ctrl/Cmd+Y or Ctrl/Cmd+Shift+Z
Save: Ctrl/Cmd+S
Toggle analysis: Ctrl/Cmd+Shift+A
Resign: Ctrl/Cmd+Shift+X
Full Screen: Ctrl/Cmd+Shift+F (or the Full Screen button)
Toggle layout: Ctrl/Cmd+Shift+L
Toggle toast messages: Ctrl/Cmd+Alt+T
Playback play/pause: Space (during playback)
Bot pause/resume: Space (during live play when a bot is enabled and playback is not active)
Bot speed: Alt+↑/Alt+↓ (when the AI speed control is available)
Playback speed: Alt+Shift+↑/Alt+Shift+↓
Show keyboard shortcuts: Ctrl/Cmd+Shift+? (also works as Ctrl/Cmd+Shift+/)
Right-click menu: Right-click outside the board → Show Keyboard Shortcuts

Analysis mode (private sandbox)

Toggle via the Analysis button or Ctrl/Cmd+Shift+A.
In online rooms, moves made in Analysis mode are local-only and are not submitted to the server.
Your opponent does not see your Analysis mode or analysis moves.
AI/bots are paused while analysis is enabled, and restored when you exit.
Move any piece freely: Both sides' pieces are selectable—click a piece of either color to move it using legal moves. The evaluation panel stays live so you can assess each hypothetical position. In Engine mode, Columns Chess uses an approximate Stockfish read of the board because stack-specific tactics are outside standard chess rules.
Leaving Analysis returns you to the live game state.

Board visualization (arrows & highlights)

Draw arrows (desktop): Right-click and drag from one square to another.
Knight arrows: If the drag is a knight move (2×1), the arrow draws as a 90° “L” shape.
Highlight squares (desktop): Right-click a square (default, or press S).
Circle highlight: Press C while / after right-clicking.
Push pin: Press N while / after right-clicking.
Protect: Press P while / after right-clicking.
Number labels: Press 0-9, then right-click a square.
Remove: Press X on desktop to arm selective erase, then right-click a square — removes number first, then pin/protect, then square/circle.
Colors (desktop): Orange (default), Shift = Green, Ctrl = Red, Alt = Blue.
Clear all annotations: Alt+X (works even on layouts where Alt changes the typed character).

        Touch / tablet (Analysis mode): On touch devices, a small swatch
        palette appears below the board while Analysis is enabled.
      

Pick color: Tap a color swatch (Orange/Green/Red/Blue) to set the annotation color.
Draw arrows: Touch and drag from one square to another.
Play moves: Tap the Play type button, then tap squares to move pieces. (Turning on Play disables Erase.)
Place annotation: Tap a type button (Square / Circle / Pin / Protect / 0-9) then tap a square.
Remove annotation: Tap the Erase button then tap a square; or tap the Remove type button (X) then tap a square — removes number first, then pin/protect, then square/circle.
Clear all: Tap the Clear swatch (black square with a red X).

Left panel → Options

Show board coordinates toggles A–H and 1–8 labels.
Inside squares draws coordinates on the board itself: lowercase file letters in the bottom row (lower-right of each square) and rank numbers in the left column (upper-left of each square). The label color uses the opposite square’s base color for contrast.
Flip Board rotates the board 180° so Black is on bottom; coordinates update to match the viewer.
Show toast notifications shows center-screen toasts (e.g. Check!).
Sound effects toggles subtle UI/move sounds.

Left panel → Option Actions

New Game starts a fresh game.
Save Game downloads a JSON save file.
Include move times for Save Game controls whether per-move timing is saved in the JSON file.
Load Game restores a previously saved JSON file.
In Playback, Use recorded move times replays moves using the saved durations instead of the fixed speed slider.
Undo / Redo step backward/forward through the local move history. They enable only when an undo/redo is possible.
Resign concedes the game.

Right panel → Theme

Board changes checkerboard colors (Classic/Green/Blue/Stone/Burled Wood/Candy).
Theme changes piece style (Discs/2D/3D/Neo/Candy).

Tip: if something looks wrong, include the exact move sequence and (if online) the room ID when reporting a bug.

Notation

In move history, → indicates a non-capture move and × indicates a capture.

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