How to Play CoreSquares
The core idea
Every chess piece lights up the squares it controls. Place pieces on the board so that their combined coverage lights every target square. That is the entire game in one sentence.
Self-lighting means each piece lights two things: the squares it would attack in chess, and the square it sits on. A rook placed at the center of a row lights the entire row plus the entire column plus its own square.
Controls
Drag a piece from the tray onto the board, or tap a square to drop the piece you are holding. As you drag, a live preview shows exactly which squares the piece will light, so you can line it up before you let go. On a phone the held piece floats one row above your fingertip so your thumb never hides it.
Drag preview shows which squares will light
Light every target to solve the puzzleThere is no undo, drawn from the chess principle of committing to a move. If a placement is not working, tap Restart to clear the board and start the attempt over. Restarting never erases your completion record, and the campaign has no lives and no timer, so you can try as many times as you like. Stuck on one level? Skip it and come back later; it will not block the rest of the world.
The pieces
Six chess pieces, each introduced in the School world. You do not need to know chess to play. The early levels teach each piece by feel.
| Piece | Attack Pattern | Learned in |
|---|---|---|
 Rook | Straight-line control along ranks and files | Kindergarten |
 Bishop | Diagonal sweeper across the board | 3rd Grade |
 Queen | The most powerful piece: rook and bishop combined | 4th Grade |
 Knight | L-shaped jumps that leap over everything | 6th Grade |
 King | Tight local control in all 8 directions | 8th Grade |
 Pawn | Forward diagonals only, the most limited piece | 10th Grade |
World mechanics
School teaches the pieces. Every world after it bends one rule:
- Lava — blocked cells. Obstacles you cannot place on. They stop rook, bishop, and queen beams before them, and never light up themselves. A knight jumps over them.
- Ice — frozen targets. A target that needs two different pieces covering it at once. One piece that hits it on two lines still counts as one.
- Forest — void cells. Holes cut out of the board. Beams stop at their edges and knights cannot land on them, so every piece covers less than you expect.
- Storm — enemy sentries. Fixed enemies that block your beams and guard red squares you cannot place on.
- Cosmos — portals. Linked pairs that send a beam out of the twin portal, still traveling the same way, to reach targets no straight line could.
- Beach — beam reflection. Diagonal beams bounce off the board edges once. Straight rook lines do not.
- Night — the dark board. The board is hidden and the piece you hold is a flashlight that reveals nearby targets. Place from memory, then submit to fire the beams.
Tech, Aqua, and Burger combine these ideas and scale the boards up, with Burger reaching 12x12. See every world →
Hints
A hint is a nudge, not the answer. The game solves the board behind the scenes and shows you the first move of a winning line; you place the rest yourself. You begin with a few free hints and earn more by solving the daily puzzle and clearing worlds. If you would rather not spend one, the drag preview is always there to help you read the board.
Game modes
- Campaign: 11 worlds, 258 levels, no timer. Worlds unlock in order as you clear them. Details →
- Daily Puzzle: one board a day, the same for everyone, gentle on Monday and hardest on Sunday. Solve it for a hint and a streak.
- Clocks: speed runs built from generated puzzles. Beat the 3 Min or 5 Min clock, or play Survival until three wrong answers end the run.
Settings and accessibility
In Settings you can lock the screen to Portrait or Landscape (or leave it on Auto), turn on Reduced Motion to cut the animations, and toggle sound and vibration independently. You can also reset your progress, which keeps your earned badges, lifetime stats, and hint balance.
Tips
- Read the board before placing. Look at which targets are clustered and which are isolated.
- Start with the most constrained piece. If you have a pawn, its correct position is often obvious because it covers so few squares.
- Look for squares that only one piece type can reach. If a target is on a diagonal that no rook can hit, it must be covered by a bishop or queen.
- Use the drag preview. Hold a piece over different squares and watch what lights up. This is your primary tool for reading the board.