| Min number of participants | 1 |
| Age | 8+ yrs. |
| Safety support by adult | Not required |
| Min duration | 10 min. |
| Cost | Low |
| Environment | Indoor / Outdoor |
Filling a grid of numbers one logical deduction at a time — a compact, screen-free puzzle that fits in a pocket and absorbs attention through even the longest delay.
A grid-division puzzle where you split the whole grid into regions (polyominoes) so that every cell's number equals the size of the region it belongs to — and no two same-sized regions touch edge-to-edge.
A two-player pencil-and-paper grid game: each player secretly places a fleet of ships on a hidden grid and takes turns calling out coordinates, trying to sink the opponent's ships before their own are found.
