Position-Based Expansion is a unique feature where a special wild symbol directly triggers the physical expansion of a pre-existing activated position on the game grid.
Unlike standard expanding wilds that grow themselves or general reel expansions that affect the entire grid, this wild specifically targets and modifies another game element.
When the designated wild lands, it causes a specific collection or activation zone (e.g., a 'Catch Frame') to increase its size.
This expansion typically converts the target position into a larger 2x2 block.
The primary goal is to enhance the collection potential or interaction area of the activated position, leading to greater rewards.