Animating a jump for a video game?

How would one go about this? If this was for a movie, I would simply animate the jump like any other action. However, since this is for a video game I can’t do that. Technically speaking, the animation on a game character is just a visual representation of what he’s doing at the time. In a jump, the character physicaly lifts off the ground, the programmers would be doing this part. Yet how would I make it look good. Do I have him go through the jumping motions without leaving the ground? do I make him actually do a jump, (and when in game he will just be physically jumping resulting in a higher jump than I animated) then there’s the issue of airtime, and landing. If you jump in place vs jumping onto something. Both have a different amount of airtime. The could be drastically seen if you jump off of something very large.

Also, I we don’t know how high we want him to jump at the moment.