One of the most beautiful, awe inspiring landscapes to explore in a video game is none other than the floating island. Imagine being surrounded by plains, forests, mountains... and blue sky and clouds as far as the eye can see. As beautiful as they are though, just how do they stay in the air?
Some games offer a semi-plausible explanation, such as giant fans on the bottom of islands, or simply "It's magic." Other games, however, offer no explanation whatsoever, and the islands simply float. The force of gravity should be pulling them down, and there isn't some giant hand holding it up, so there's no physical force pusing it up against gravity. This leaves two options:
1) A force field, likely caused by magnetism, creates an upward force on the island which counteracts gravity.
2) The island pushes something else (air) down. The impulse of the air over time causes an oppsite force on the island which counteracts gravity.
Both of these are semi plausible, until you actually factor in entering and exiting the island, which changes the island's mass, and would cause it to move due to unbalanced forces. In the end, maybe the "It's magic" definition is better.