Falling, growth, and contact

Sand and plants

Sand keeps falling when there is space below it. It can fill holes, but cannot reliably form a suspended bridge.

Wood grows Leaves in adjacent empty cells. Moss spreads Vine into nearby empty cells during placement resolution; Vine is passable. Bamboo grows upward periodically and disappears when it loses support below.

Their timing differs. Sand and Wood change as the battle runs; Moss spreading and Bamboo growth are tied to placements. Waiting does not advance every plant’s growth.

Fragile materials

Placing a non-liquid piece checks for old Glass directly below the newly placed cells and Cactus to their left and right. Matching old blocks break. Cells within the same newly placed piece do not break one another this way.

Breaking a block is not a line clear. Removing Glass may open useful space, but it can also leave a hole in an almost-full row.

Sponges

Each newly placed Sponge cell searches for liquid within three orthogonal steps, counting horizontal and vertical distance together. On finding a liquid cell, it empties that cell and becomes wet. It does not drain a whole pool at once.

A Sponge cell becoming wet for the first time deals 3 base direct damage. Sponges are useful for local liquid removal; this placement effect does not continuously absorb liquid afterward.

See Fire, Liquids and corrosion, and Damage.