Does a gnoll's Rampage trait actually give it bonus movement?

Question

Gnolls pretty universally have the trait Rampage:

When the gnoll reduces a creature to 0 hit points with a melee attack on its turn, the gnoll can take a bonus action to move up to half its speed and make a bite attack.

Until recently, I assumed the "move up to half its speed" was just that, free movement. Now, I'm not so sure. Have you looked at the wording of the dash action recently?

When you take the Dash action, you gain extra movement for the current turn. The increase equals your speed, after applying any modifiers. With a speed of 30 feet, for example, you can move up to 60 feet on your turn if you dash.

Explicitly, it gives you extra movement that turn, whereas Rampage fails to specify one way or the other. You can't even prove it's meant to give you extra movement by contradiction, since the trait makes sense even if it doesn't give extra movement - the gnolls bashes an opponent to death, then can bite another one, as long as it doesn't have to move more than 15' to do it.

Ideally, I'd like some official guideline on how to word a feature (spell, action, item, etc.) to say it costs movement vs. how to word it to say it gives bonus movement.

Answer 1

An action that lets you move a certain distance is separate from the pool of movement you have on your turn

There's a difference between an action or bonus action that grants you additional movement on a turn, and an action or bonus action that involves you moving as part of it.

The description of the Dash action says "you gain additional movement for the current turn" equal to your current speed. This references the general rules for movement and position, which state:

On your turn, you can move a distance up to your speed. You can use as much or as little of your speed as you like on your turn, following the rules here.

Your movement can include jumping, climbing, and swimming. These different modes of movement can be combined with walking, or they can constitute your entire move. However you're moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving.

Other rules on movement, such as breaking up your move, also apply to this. In particular, the rule on moving between attacks states:

If you take an action that includes more than one weapon attack, you can break up your movement even further by moving between those attacks. For example, a fighter who can make two attacks with the Extra Attack feature and who has a speed of 25 feet could move 10 feet, make an attack, move 15 feet, and then attack again.

Say you're 30 feet away from an enemy, and you have a speed of 30 feet. If something (e.g. the rogue's Cunning Action feature) lets you use a bonus action to Dash, you could move towards the enemy, use your action to attack them, Dash as a bonus action, and then use your remaining 30 feet of movement to move away from the enemy. (Moving away from the enemy might provoke an opportunity attack, but that's irrelevant to the current issue.)

In contrast, something like the gnoll's Rampage trait says:

When the gnoll reduces a creature to 0 hit points with a melee attack on its turn, the gnoll can take a bonus action to move up to half its speed and make a bite attack.

Notably, this doesn't reference the pool of movement that the gnoll has on its turn at all.

The gnoll has a speed of 30 feet, so it normally has 30 feet of movement for a turn. (If it takes the Dash action, it gains an additional 30 feet of movement for that turn, for a total of 60.) This pool of movement can be used freely on its turn, before or after its attacks (or between them, for the other kinds of gnolls that have Multiattack).

However, the Rampage trait doesn't relate to the gnoll's pool of movement on its turn at all. Consider how the Rampage trait would work if the gnoll doesn't have to move the full distance (i.e. half its speed) to reach another enemy that it can bite.

For instance, say enemy A is 30 feet away from the gnoll, and enemy B is 10 feet behind enemy A. The gnoll uses all of its movement to move 30 feet forward, then uses an action to attack and kill enemy A. The gnoll then uses its bonus action (thanks to the Rampage trait) to move just 10 feet forward and bite enemy B. After this occurs, the gnoll can't move any further – it already used its whole pool of movement on its turn to get up to enemy A.

If the gnoll doesn't move the full distance allowed by the Rampage action, the remaining amount doesn't carry over, because it's not added to its pool of movement available for the turn; it's just a separate thing that lets it move once (up to) a certain distance.

Answer 2

The Dash action is actually a good example of how to tell the difference; it adds to your available movement when it says:

you gain extra movement for the current turn. The increase equals your speed

While rules for movement do not explicitly use the phrase "available movement", the concept is clearly baked into them:

On your turn, you can move a distance up to your speed. You can use as much or as little of your speed as you like on your turn, following the rules here.

Your movement can include jumping, climbing, and swimming. These different modes of movement can be combined with walking, or they can constitute your entire move. However you’re moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving.

This last sentence tells us that we must keep track of how much we have moved in a turn, or in other words, you have a certain amount of movement available to you on your turn; the Dash action adds to this amount of available movement.

In contrast, the Gnoll's Rampage feature functions without respect to your available movement. It is a separate feature from "your movement" that allows you to move when you use your bonus action. You just do what the feature says:

take a bonus action to move up to half its speed

If this feature was supposed to interact with your available movement, it would say that. You just do what it says, and it works, even if your available movement for this turn is 0 (but speed is not 0).

Answer 3

Yes,ish

To understand this, we have to cover how your movement works.

To start off, you have an amount of movement you can do per turn that you get from your speed. Which, as per this question, you can split up however you want however many times. What dash is doing is increasing the amount of movement you can do, not increasing your speed, hence its wording.

What Rampage is specifying can be written as the following:

the gnoll can take a bonus action: move up to half its speed, then make a bite attack.

So it uses half of your speed (not your current movement), and then make a bite attack as part of one thing. Not adding anything to your movement, just part of the bonus action.