Desert

Desert is a terrain type that often features in the series. It usually grants a small Avoid bonus, while greatly decreasing the movement of units, especially those riding on horses. In most games, magic-type units (not riding on horse) can walk on this terrain type without any adverse benefits. According to Sephiran in Fire Emblem: Path of Radiance, the spirits employed by magic units gives them better footing.

Trivia

 * In Fire Emblem: Rekka no Ken, it is the only terrain that has reduced movement penalities while it rains, which actually makes it more easily traversable. Unfortunately there are no maps with rain that feature this terrain.