The goal of Re-Nullum is to clear the board on each level by connecting numbered tiles.

To connect a tile, click on it and drag towards a neighboring (in a horizontal or vertical direction) tile.

If the numbers in each tile match, both pieces are removed from the board.

Otherwise, the pieces connect to form a new single bigger tile; with the numbers on each previous tile added together to get the new tile's value.

Levels 8, 9, 26, 32, 33, 38, 39, 40 use the "remove tile(s)" mechanic where at the start of a level you are given a number of tiles (ranging from 1-3) that must be removed from the board before trying to solve it. To pick a tile to remove just click on it; you can not choose to remove fewer (or more) tiles then the number given or pick to remove the special grey tile from the board if the level contains one.

Levels 20, 21, 34, 39, 40 use a "grey tile" mechanic where one chosen tile will appear grayed out on the board and is unmovable and can't be combined with other tiles. Only when there is only one other tile on left on the board with it will the grey tile turn into a normal tile that can be interacted with.

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