How does sprite customization in 2D games work?
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I´m working on the design of a new game concept at the moment and I would like to know how to handle a customization of sprites. (In 2D that is, hence the topic.)

This is my scenario: The player will have a tower containing 3 floors (or more). Each floor can be replaced by another "piece", i.e. a blue floor, a fire floor, a stone floor.

With the little knowledge of game development I have, creating a sprite for each possible combination is probably not a good idea, since the size of the game file will be HUGE.

So, how does developers solve this? Do you put a standard position and just replace the sprite itself? Any advice or information about this would be great.

Regards.