1. Pick a piece
Tap one of the seven shapes (I, O, T, S, Z, J, L). Press Rotate or the R key to turn it 90°.
Black XORcerer CMY XOR spells
Goal: make Your board match the Target exactly (shape and color). You place tetromino stamps.
Stamping uses XOR (toggle): stamping the same CMY color on a cell twice cancels it back.
Color = 3-bit CMY state per cell. Each cell stores three on/off bits: Cyan (C), Magenta (M), Yellow (Y).
A stamp flips exactly one bit (C or M or Y) over its footprint.
- One bit on: pure C/M/Y
- Two bits on: mix (C+M, C+Y, M+Y)
- Three bits on (C+M+Y): shown as dark/black
- Zero bits: empty/paper
Overlaps matter because XOR flips bits: if a cell already has Cyan and you stamp Cyan again, Cyan turns off.
Difficulty
Grid
Moves
0
Move limit
—
Keyboard (only the essentials; no duplicates):
I O T S Z J L pick a piece • R rotate piece • 1/2/3 choose Cyan/Magenta/Yellow • U undo last stamp • Y redo • H toggle mismatch hints.
(No keyboard shortcuts for Reset, New, or Solution to avoid conflicts.)
I O T S Z J L pick a piece • R rotate piece • 1/2/3 choose Cyan/Magenta/Yellow • U undo last stamp • Y redo • H toggle mismatch hints.
(No keyboard shortcuts for Reset, New, or Solution to avoid conflicts.)
Black XORcerer
CMY color puzzle
Pick a piece (I/O/T/S/Z/J/L), pick a color (1/2/3), hover, click to stamp.
Mismatch: —
Level: 1
Recipe: —
1
Study the target
Target
2
Choose a stamp
Drag to the board · or tap to select
3
Choose a color and stamp
Same color twice cancels
Solved!
As few as the puzzle itself
History