Meowdoku!: How to Place a Safe X on a Four-Cell T Shape

When you encounter a four-cell T-shaped colored region in Meowdoku!, mark an X directly opposite the center stem across the three-cell bar. You do not need to guess where the cat belongs. Because every colored zone requires exactly one cat, and cats cannot touch each other or share a row or column, every possible placement inside a four-cell T eliminates that specific neighboring square.

Why the Target Cell Is Always Invalid

A standard four-cell T tetromino consists of a three-cell bar and a single stem cell protruding from the middle. If you orient the bar horizontally across three cells (Left, Center, Right) with the stem extending downward, the target cell is the square directly above the Center cell.

Testing all four potential cat locations confirms that the square opposite the stem can never contain a cat:

Because the region contains only these four cells, the cat must occupy one of them. Since all four choices block the exact same cell outside the region, that cell is guaranteed to be safe to mark with an X.

How to Apply the Rule Across Rotations

This deduction works in all orientations. Look at the stem cell and look directly across the center of the bar:

• Stem points down: Place the X immediately above the center of the horizontal bar.
• Stem points up: Place the X immediately below the center of the horizontal bar.
• Stem points right: Place the X immediately to the left of the center of the vertical bar.
• Stem points left: Place the X immediately to the right of the center of the vertical bar.

Grid Boundary Check

If the three-cell bar sits flush against the outer wall of the grid and the stem points inward, the target cell lies off the playing board and provides no actionable mark. The technique is useful when the stem points toward or touches the perimeter, pushing the guaranteed X deeper into the active grid where it can narrow down adjacent colored regions.

Verification Checklist

Before placing the mark, confirm that the shape meets all structural conditions:

1. Verify cell count: The shape must consist of exactly four connected squares in a single color group. If the region has a fifth cell or forms an extended cross, the proof fails because an extra cell might not attack the target coordinate.
2. Confirm stem alignment: The stem must connect directly to the center square of the three-cell bar, not to either end (which forms an L shape rather than a T).
3. Check the board state: Mark the confirmed X immediately to reduce the available options in whatever neighboring region covers that tile.