RAW, you cannot become invisible via moving fast
As the other answers have stated, there are no rules that imply this. When a monk reaches 18th level, they gain access to the Empty Body class feature (PHB, p. 79):
Beginning at 18th level, you can use your action to spend 4 ki points to become invisible for 1 minute. During that time, you also ...
Coming from a D&D point of view...
The game becomes a lot more mobile, speed is more valuable, the concept of front-liner diminishes, and being at range is either difficult or not important.
I tried this for a one-shot once with a couple of new players, and we removed OAs for simplicity's sake. The more experienced players at the table had some fun ...
Variant Human (30ft) with Mobile Feat (+10ft) with 2 Monk levels (+10ft from Unarmored Movement, and Step of the Wind) + 3 Totem Barbarian levels (+15ft Elk Totem during Rage) + 2 Fighter Levels (Action Surge).
Mr. Bolt has to run 100m in 9.4/s, or 328ft in 9.4s, or 210ft/turn (average speed). His base speed is 50ft.
As a setup, Bolt rages to ...
There is no such speed in D&D 5e. You will have to add it yourself.
There is no speed in D&D 5e that causes spontaneous invisibility.
Since you are deciding that there is such a speed, but D&D can’t tell you what it is, it’s up to you as the DM. You’ll have to pick a speed and create your own house rule that says, “a Speed of [whatever you ...
As of the 2018 Errata, the Athlete feat has been changed
Athlete (p. 165). The third benefit should instead say climbing doesn't cost you extra movement.
—Errata: Player's Handbook, 2018
Because of this change, the Athlete feat would allow a Centaur to ignore all extra costs associated with climbing. The technicality of ignoring "halved" movement ...
Swimming is not flying
As far as I am aware, flying is never defined as a game term, which means the word takes its normal English meaning: moving through the air under one's own power. I don't think most people would describe underwater movement as flying (except metaphorically).
You can probably "fly" at half speed underwater
The rules for swimming ...
You already have the proper solution
A spell's text details the spell's effects — the only thing the spell does. Any additional effects are up to the DM. The DM role is crucial, because rules do not cover all the corner cases. This is a corner case, so you can not figure out the "correct" answer based on rules only, without the DM.
I thought it was quite ...
No, they can't
The base speed refers to the land speed of any creature, and a speed of 0 means they can't move on land. This is further reinforced in the Monster Manual section on speeds (p. 8):
All creatures have a walking speed, simply called the monster's speed. Creatures that have no form of ground-based locomotion have a walking speed of 0 feet.
Most of what you're describing is just flavor text. In game terms, your player wants to:
Move adjacent to the monster (through another character's space)
Attack the monster
Per PHB page 191, Moving Around Other Creatures:
You can move through a nonhostile creature's space.
Your player can dress it up however they like, but it's basically normal ...
You cannot move between the attacks of an action unless those attacks are weapon attacks
What we can see from looking at the rules is that there exists a section on "Moving Between Attacks" which 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 ...
You can continue the movement after losing concentration
Expeditious Retreat allows you to take the Dash action as a bonus action.
When you take the Dash action, you gain extra movement for the current turn.
At the point at which they take the Dash action they 'gain extra movement for their current turn'.
If their concentration on Expeditious Retreat is ...
There are examples of magic items that do grant as swimming speed, and they state so explicitly. The Cloak of the Manta Ray (DMG pg. 159), for example, states that "you have a swimming speed of
Since the Gloves do not do so, they do not grant a swimming speed. They do exactly what they say they do: remove the speed penalty from being ...
The closest RAW example of this is the Quickling
These creatures are described as "so fast their movement is blurry" and their base movement speed is 120ft. You can still make Opportunity Attacks against them, although those are made with Disadvantage. So are normal attacks, unless you manage to reduce their speed to 0.
Perhaps you can use some of this as ...
You can get there without any levels with favorable rulings, but otherwise level 1
The character to run the sub-2-hour marathon at level 1 with three of the following selections (only one of which can be a class, and only two of which can be a feat):
The Barbarian class (for Fast Movement)
The Cleric class with the Celerity Domain (Spell ...
This won't work
Target of the silence spell is a point. It neither an object nor a creature:
20-foot-radius sphere centered on a point you choose within range
A point is fixed in space, unless your DM says otherwise. If a spell can be cast on an object so its effect moves with this object, its description explicitly says so. See the darkness spell for ...
Under some conditions, a speed that has "become zero" can be increased magically, as discussed in this question.
If you "can't move", then changes to your base speed have no effect.
Also, "can't move" does not imply "can't take an action". This is indicated by the fact that all conditions that use the phrase "can't move" include the condition Incapacitated ...
Speed is a game noun
The basic rules define speed as:
Every character and monster has a speed, which is the distance in feet that the character or monster can walk in 1 round.
On your character sheet this is probably listed as "speed: 30ft" or something similar. Anywhere the game says "speed", it is talking about this speed. You use it for standing up, ...
The monster will usually disturb the material it burrows through.
Consider the Earth Elemental:
Earth Glide: The elemental can Burrow through nonmagical, unworked earth and stone. While doing so, the elemental doesn't disturb the material it moves through.
The Earth Elemental (and the Xorn monster) can just glide through earth with its Burrow speed, ...
Getting up from prone uses movement, but is not the same as moving.
The Tabaxi's Feline Agility trait states (VGtM, p. 115):
Once you use this trait, you can’t use it again until you move 0 feet on one of your turns.
While standing up from prone uses some of your movement, it is never described as "moving":
You can drop prone without using any ...
I have my own issues with the answers on the linked question, and have posted an opposing answer there, but I will rehash the point here.
The rules for movement on a grid state (PHB, p.192)
Rather than moving foot by foot, move square by square on the grid. This means you use your speed in 5-foot segments.
This does not say all movement distance (or ...
This won't work, for several reasons
It's debatable whether a bag of holding's interior counts as a separate plane of existence in the way a portable hole does. If the bag doesn't open into a separate plane, then this plan obviously doesn't work. However, even if it does, the plan still doesn't work. First of all, measuring distance across planes is ...
The Wyvern is unable to pass through the Sorcerer's space and must move around them or attack them.
It would seem there are no additional rules that come into play here, either from invisibility or movement, so unless your monster has a trample ability, it would not be able to move through the Sorcerer's space, as per your quoted movement rule. (It feels a ...
Movement speed doesn't have any scaling or multiplier based on size
Movement doesn't scale based on size/space - no matter how big the creature is, if it has a movement speed of 30 feet, it can only travel up to 30 feet (six squares at the standard grid scale), so if for instance it travelled in a straight line the front of it would be 30 feet from where it ...
This works, the spell water walk defines snow as a liquid for mechanical purposes.
Water walk says:
This spell grants the ability to move across any liquid surface--such as water, acid, mud, snow, quicksand, or lava
Here snow is described as a liquid for mechanical purposes. I argue that this demonstrates that for mechanical purposes, the rules are ...
The enemy must actually fully end its turn there
The Scout Rogue's Skirmisher feature states:
You can move up to half your speed as a reaction when an enemy ends its turn within 5 feet of you. This movement doesn't provoke opportunity attacks.
The section on "The Order of Combat" states:
4. Take turns. Each participant in the battle takes a turn in ...
The rules don't specify that
• You attempt to climb a sheer or slippery cliff, avoid hazards while scaling a wall, or cling to a surface while something is trying to knock you off. (Basic Rules p. 62)
The PC rolls an ability check when the DM calls for one.
An ability check tests a character’s or monster’...
Their flying speed is 30.
These rules do not conflict, so there's no need for "specific vs. general" silliness. Fly gives you a flying speed of 60, in the same way that, say, being an elf gives you a walking speed of 30. Exhaustion then cuts it in half.
Exhaustion doesn't say whether it applies to all your movement speeds or just walking speed. However, it ...
You can move or attack, not both.
As stated in the Ready action description on page 193 of the PHB:
Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it.
Yes, but only up to 1 hour.
Nowhere in the rules does it say that an elf has to remain stationary when they Trance, so it does appear possible (though problematic for avoiding falling prone). However, they are still limited in how long they can walk for.
The rules for Long Rests state
If the rest is interrupted by a period of strenuous activity—at least
No, a horse can't travel this quickly
The rules you've found in the DMG under Special Travel Pace aren't for mundane methods of locomotion like riding a horse:
A character bestride a phantom steed, soaring through the air on a carpet of flying, or riding a sailboat or a steam-powered gnomish contraption doesn’t travel at a normal rate, since the magic, ...