Adding some extra options for flying movement, to allow faster movement when descending.

A falling creature moves vertically downwards at a speed of 600ft in the first round, and 2,000ft in subsequent rounds.

Once you begin falling, it's a Fly DC 10 check to recover, but you are considered to have been plummeting at high speed the previous round (see below).

When flying, for every 5ft you descend you can move 5ft horizontally for free. If you have a fly speed of 30ft, then you can perform a controlled descent of up to 60ft/round, and move horizontally as much as 60ft as well.

For every 5ft you ascend, you must also move 5ft horizontally. This costs 10ft of movement.

If you want to avoid the 5ft of horizontal movement when ascending, you must make a Fly check DC 20, but it still costs you 10ft of movement. You only make one check per round, at the point you first want to avoid the horizontal movement. If you fail by 5 or more, you fall 600ft if it's in your first move action, or 300ft if it's part of your second move action.

* If this is attempted two rounds in a row, difficulty increases by +5 each round and you become fatigued if you fail. Once fatigued, you cannot try to make triple or quadruple moves.

If you try to make a triple or quadruple move and you fail, then you must move at full double speed in the direction you intended.

Descending means descending at a 45° angle or greater (i.e. you descend at least as far as you move horizontally). If you did a triple or faster descent in the previous round, you must descend at least a distance equal to your base move rate.

• DC 10: Descend at less than full base speed after a fast descent
• DC 20: Descend at less than half base speed after a fast descent
• DC 30: Hover after a fast descent.

Plummeting means descending directly down, no more than 5' horizontal movement per 30' of vertical movement. I f you plummeted at more than double speed, then the following round, you must descend at full double speed downwards, and need to move horizontally at least half this distance.

• DC 10: Descend less than full double speed.
• DC 20: Descend less than full base speed.
• DC 30: Descend less than half speed.
• DC 40: Come to a hover.

Add +10 to the DC if you don't also move horizontally at least half as far as you descend.

If you hit the ground (or a wall) because you were unable to pull out of a triple or quadruple speed descent or plummet, then you cannot make a fly check to negate the damage.

If you fail to plummet or descend at a faster rate, then you move at the maximum speed that your fly check allowed. You cannot use flyby attack when moving at triple or quadruple speed, but you can charge.

An Old White Dragon has a fly speed of 200ft with a Fly skill of +12. It is 800ft above its prey, and decides to plummet directly down to it. It makes a DC 20 plummet check, so drops 600ft, leaving it 200ft up.

The following round, it tries to pull up. To come to a stop on the ground is a single move of 200ft, which is less than a double move so requires a DC 10 fly check (which it will make automatically). Unless it also moves at least 100ft horizontally though, then the check will be DC 20.