What does "leap off" mean?

In this sentence, "Over the years, they’d built snow forts together and leaped off backyard sheds together" what does "leap off" mean?

Without knowing the context more fully, this is a bit of a guess, but here goes:

The fact that the phrase describes the people building snow forts together leads me to think the entire description is during winter. Given the right conditions, snow can form a soft surface to jump onto.

The sentence definitely means the people jumped off the shed roof onto the ground together, but may imply that it was done into a snow pack for cushioning or lessened distance to fall. This is an activity children, in testing their daring, engage in. The passage therefore describes bonding through exciting activity.