How is the movement cost of standing from prone affected by changes in speed?

[RickAllison]

The most direct way I think I can explain is by example. As I understand it, it takes half of your movement to stand up from prone.

1: Wizard is knocked prone; spends half his movement (15 feet) to stand up, then casts Longstrider so speed is 40 and he has 25 feet of movement left.

2: Wizard is knocked prone; casts Longstrider and spends 20 feet of movement to stand up.

Are those right? Or is there something I’m missing, like it only counts your base speed. Does a monk spend more movement to stand up? Would an Elk Barbarian knocked prone be better off standing up before Raging?

[diplomancer]

I think it's case 2. It's always half your speed. Think of it as "it takes 3 seconds to get up from prone" and it makes sense.

As for the longstrider case, I'd say that he can still use only 20' of movement, but other DMs might think it differently.

[Lord Vukodlak]

The most direct way I think I can explain is by example. As I understand it, it takes half of your movement to stand up from prone.

1: Wizard is knocked prone; spends half his movement (15 feet) to stand up, then casts Longstrider so speed is 40 and he has 25 feet of movement left.

2: Wizard is knocked prone; casts Longstrider and spends 20 feet of movement to stand up.

Are those right? Or is there something I’m missing, like it only counts your base speed. Does a monk spend more movement to stand up? Would an Elk Barbarian knocked prone be better off standing up before Raging?
It takes half your movement, if something increases your speed it takes more, if something decreases your speed it takes less. If your speed is zero then you can't stand up at all.
Now to prevent shenanigans. For something that increases your base speed like longstrider or an Elk Barbarian's rage. It wouldn't make a difference what order you did it in, the result would be the same. It'd cost half your speed.

Now a Rogue's cunning action can give you an additional move that would be unaffected.


Standing up takes time and you no longer have that time available for movement. Being able to run fast doesn't mean you can get up off the ground sooner. As the above poster said "it takes 3 seconds to get up from prone."

[Chronos]

A rogue's cunning action doesn't give you an extra move. It lets you use Dash, which increases your amount of movement, just like Longstrider does.

[Lord Vukodlak]

A rogue's cunning action doesn't give you an extra move. It lets you use Dash, which increases your amount of movement, just like Longstrider does.
Dash gives you extra movement it doesn’t increase your base speed.
Longstrider adds 10 to your base speed.
Dash is spending an action to move up to your base speed.

[Laserlight]

Whatever your speed may be, you spent half of it to stand.

[Arcangel4774]

Id suspect you are right in that the order matters. This assumption is based on the rules for changing movement types. Although its a loose comparison i see it as a precident for applying used movement to max movement. Nothing seems to imply that movement is halved, just that you use half your movement.

[ProsecutorGodot]

Now to prevent shenanigans. For something that increases your base speed like longstrider or an Elk Barbarian's rage. It wouldn't make a difference what order you did it in, the result would be the same. It'd cost half your speed.

I don't think this is actually true, you're movement for the turn is tied to your speed but the cost of standing from prone is tied to your speed at the time you're standing from prone. The order does matter. Keep in mind that "Movement" and "Speed" are different game terms. Relevant PHB text below:

Movement and Position: 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.

Being Prone: Standing up takes more effort; doing so costs an amount of movement equal to half your speed. For example, if your speed is 30 feet, you must spend 15 feet of movement to stand up. You can't stand up if you don't have enough movement left or if your speed is 0.

If you haven't moved and you stand up from prone with 30ft speed, you expend 15ft from your speed and have a remaining speed of 15ft. Adding 10ft using Longstrider makes your speed 25ft. It wouldn't make a whole lot of sense for someone to cast Longstrider and only gain half the benefit of it after they'd already paid the price to stand from prone.

If you cast Longstrider first rather than standing under the same premise as above and now are prone with a speed of 40ft, standing from prone costs 20ft and you would have 20ft remaining for the rest of your movement.

Dash is a dynamic modifier though:

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.

Any increase or decrease to your speed changes this additional movement by the same amount. If your speed of 30 feet is reduced to 15 feet, for instance, you can move up to 30 feet this turn if you dash.
So for Dash, the order doesn't matter. If you were, for example, an Arcane Trickster who opted to take Longstrider as one of their non restricted spells it wouldn't matter whether you cast Longstrider first or chose to Cunning Action Dash first.

All that said though, I personally would avoid playing gotcha with the players on whether they did these things in the proper order. The fact that there is an appropriate order in this case is, in my opinion, a flaw in the design of the movement rules.

tl;dr - You've got it right in the OP but I would recommend leniency and allow the players to end up with the highest benefit that their intended actions would result in. Standing from prone takes half of your speed in movement at the point you stand, it doesn't share the text that Dash has giving it an ability to modify your movement with any further changes to your speed afterwards. Any bonus to your speed applied after standing from prone is applied in full.

[EggKookoo]

I think it's case 2. It's always half your speed. Think of it as "it takes 3 seconds to get up from prone" and it makes sense.

By RAW this is right, but I find it frustrating. If you move quickly it's perfectly intuitive to think you can get to your feet quickly. I houserule it so that it costs half of your base movement to get up.

[Randomthom]

As others have said, the best way to rationalise this is it doesn't cost half of your movement, it costs half of your time.

[EggKookoo]

As others have said, the best way to rationalise this is it doesn't cost half of your movement, it costs half of your time.

Which is a function of speed, so a faster person should consume less time.

The problem is that with, say, a monk, your greater movement distance is presented as a form of bonus distance akin to the way the new hit points you get for leveling get stacked onto your existing ones as you level. So the player with 40 feet of movement thinks of himself as having "+10 movement," which isn't unreasonable. So when they get up from prone, they expect to get up at the same "speed" as their teammate with only 30 feet of movement speed and then still having the remaining half plus that 10 feet. When I try to explain, well, no, you also consumed half of your extra speed getting up, it feels wrong. Like, the faster dude consumed more speed getting up than the slower dude?

Yes, I know, I can explain it as it consumes half your time, but that still doesn't jive intuitively with the notion that you're somehow spending more movement distance than someone who is slower than you despite performing the exact same action.

In the end, going with half-base distance doesn't break the game. That extra few feet of movement doesn't tend to cause any kind of problem. But the player is satisfied they're not being cheated somehow, and the whole thing is just more palatable from a rules perspective.

[ProsecutorGodot]

Yes, I know, I can explain it as it consumes half your time, but that still doesn't jive intuitively with the notion that you're somehow spending more movement distance than someone who is slower than you despite performing the exact same action.
You're spending more movement, sure, but at the end you still have more remaining afterwards. For class features that give you a flat bonus to Speed (again, "movement" and "speed" are different game terms) you are still faster after having been knocked prone.

The difference as far as Longstrider is concerned is that the modifier can be applied after you've already spent movement to stand. You don't spend more after casting Longstrider, why would you when you've already spent half your movement, you gain the full 10. The standing cost from prone is not a dynamic modifier like Dash is, it always costs a static amount of movement equal to half of your speed when standing.

If you have 30ft speed and spend 15ft to stand then cast Longstrider, you don't have to subtract an additional 5ft. You have already stood, no further penalty to your speed applies.

[Aimeryan]

It is more an issue with Longstrider granting the same extra movement speed after time in that turn has already passed (movement, actions, etc.). If the spell gave movement speed starting from the next turn it would all be more intuitive.

That said, there is nothing preventing a DM from ruling that you only get to use some amount of the Longstrider the turn it is cast to represent some of the increased speed it grants can't be utilised for the full duration of that turn. The books don't cover everything.