Line clears, SPIN, and COMBO

When a full row does not clear

Every cell in a row must satisfy the clear conditions. Solid blocks must have settled; empty cells need enough liquid to count as full. Moving or appearing blocks, hidden Mines, Cursed Blocks, and No Clear restrictions can prevent clearing.

Multiple clears and collapsing rows

Obsidian and Gold Blocks need more than one clear. If a row still contains surviving blocks after a clear, blocks above it do not all shift down; other cleared cells leave gaps. An untriggered Chess Piece can also survive the clear to make a move.

A row triggering a clear and that entire row becoming empty are different conditions.

Cursed Blocks prevent their row from clearing. Clearing other rows weakens one selected Cursed Block by the number of lines cleared. It is not a board-wide reduction to every curse.

SPIN

A placement is a SPIN if you rotated during the operation and the final piece cannot move one cell in any of the four directions. It is not limited to T shapes, the last input need not be a rotation, and clearing a line is not required.

A SPIN clear can use the SPIN damage multiplier. Rotating repeatedly on its own does not satisfy the trapped-position requirement.

COMBO and natural chains

The first clear establishes the starting point; later consecutive clears build COMBO. A successful placement with no clear breaks it. Selecting, rotating, and waiting do not break it by themselves.

Clearing four lines together does not add four COMBO steps. Further clears from material reactions can continue the combo. The displayed COMBO number is a count; the damage multiplier is calculated separately.

Natural chains are clears outside the immediate placement-clear step, including those caused by falling sand, mechanisms, or skills. See Damage calculation.