Q:

Rules for attacking an enemy mid-Jump

Are there any specific rules for attacking an enemy while jumping in D&D 3.5?
Say there is a flying enemy 20 ft in the air and I want to attack it with my melee weapon. I charge and assuming I make the skill check to jump 10 ft high ( which would presumably let me attack from a height of 15 ft) I attack the enemy flyer as usual.
Is this possible and if yes, what would I have to take into account?

A:

According to the rules, because landing's part of jumping, a typical creature can't jump, make an airborne attack, then land, even when making a charge
The problem is the Jump skill's anti-basketball bias. The Jump skill's check opening description details the jumping process. After adjusting the creature's Jump skill check bonus for the creature's speed and for not having a running start, that process has but two steps:

The creature makes a Jump skill check to travel some distance. The Action section of the Jump skill description says that

A Jump check is included in your movement, so it is part of a move action. If you run out of movement mid-jump, your next action (either on this turn or, if necessary, on your next turn) must be a move action to complete the jump. (PH 77)

Thus, generally, a creature that takes a move action to move up to its speed can make one or more Jump skill checks during that move action, adding the distance traveled during the jump to determine his distance moved during that move action.
But, as Jump skill checks are also included in the creature's movement, a creature need not take a move action to move solely to make one or more Jump skill checks if otherwise using its speed to move.1,2
The creature lands. Typical creatures don't have a choice. That's because

If you have ranks in Jump and you succeed on a Jump check, you land on your feet (when appropriate). If you attempt a Jump check untrained, you land prone unless you beat the DC by 5 or more.3 (PH 77)

Except for completing a jump that exceeds the creature's movement, the only way a typical creature avoids landing right after making a Jump skill check is by not making a Jump skill check. For the typical creature there's no way to increase hang time during a jump so that the jumping creature can, for example, make an attack... or dunk.

I know that's terrible, but alternative readings tend toward Looney Tunes-style gravity-defying hijinks and Mario Bros.-style double jumps.

1 If the DM allows a creature to make Jump skill checks during a 5-ft. step, remember the creature may "run out of movement" (which is, after all, only 5 ft. with a 5-ft. step) and the creature will be forced to take a move action to move as its next action to complete the jump, which is usually impossible on the same turn.
2 For example, making a charge allows movement but making a charge does not require taking a move action to move. The Rules Compendium explicitly allows a creature to make Jump checks during a charge to avoid obstacles (27).
3 An argument can be made that landing isn't prescriptive but descriptive, that this text details how landing occurs rather than mandating landing. However, under that reading, house rules must be implemented to deal with landing after a jump.

