Parity Bits
All gamesWord 1 / 4Tries left 3Failing 1 of 5
Word 1 of 4. 1 of 5 checks fail: C. 3 tries left. Cursor on bit 1, reading 0. Check A covers bits 1, 3, 4, 6, 8 and passes.
C fails; A, B, D, E passes. The flipped bit is covered by every failing check and by none of the passing ones. Check A covers 1, 3, 4, 6, 8: it wants even and reads even, so it passes — none of those is the flipped bit.
← → (or A D) move along the word · ↑ ↓ (or W S) step through the checks · Enter or Space names the bit under the cursor as the flipped one. Or click a bit to name it, or a check to focus it. Only a name costs a try; looking around is free. Click the board first, or press Tab to focus it.