Daily Challenge
A Domino Before the Square
Compare two legal domino placements on a small board. Find which one leaves room for the square, with an optional hint and checked explanation.
Difficulty: Normal
Block practice: 2 of 3. Start with Find the Only Square Space for a one-piece warmup, or try this round on its own.
Two legal moves, different results
Place a two-cell domino first, then a 2x2 square. Compare these two choices:
- Across: the domino covers A1 and B1.
- Down: the domino covers D1 and D2.
Both domino placements fit at the start. Which one leaves room for the square?
Columns are A to D; rows are 1 to 4. X means occupied, and a dot means empty. Pieces cannot overlap or extend outside the board. Nothing moves or clears. For this fixed exercise, you may choose the domino’s horizontal or vertical orientation; do not assume other games allow rotation.
| Row | A | B | C | D |
|---|---|---|---|---|
| 1 | A1: empty | B1: empty | C1: occupied | D1: empty |
| 2 | A2: empty | B2: empty | C2: occupied | D2: empty |
| 3 | A3: occupied | B3: empty | C3: occupied | D3: occupied |
| 4 | A4: empty | B4: occupied | C4: empty | D4: occupied |
Show a small hint
Find the square’s four cells before deciding where to put the domino. Does either domino choice use a cell that the square needs?
Answer: keep the square space intact
Choose Down: D1 and D2. The square can then occupy A1, B1, A2, and B2, with its top-left corner at A1.
The Across choice uses A1 and B1, so it breaks that square space. No other 2x2 opening exists. In rows 2 and 3, A3 blocks the left square and C2 blocks the other starts. Rows 3 and 4 have no complete 2x2 opening either.
The useful question is not just “Does this piece fit?” It is also “Where will the next piece fit?” A legal first move can still leave no place for the second piece.
Your next small round
Try round 3: Open Board Block Challenge, where three pieces share one board. You can stop here and bookmark that next round for another break; these are fixed exercises, with no streak or progress tracking.
For hands-on placement, play Daily Block Puzzle. Its starter board and pieces are separate from this example. Read the space management guide for more context, or visit Blockzzle for the separate browser game.