Yes, but only if the ability forces the enemy to move out of reach using their movement, action, or reaction
The rules state that only when the enemy uses their movement, action, or reaction to move out of your reach will they provoke an Opportunity Attack from you.
From the PHB:
You also don't provoke an opportunity attack when you teleport or when
Easy bit first ...
Forbiddance. The vampire can't enter a residence without an invitation from one of the occupants.
The vampire can't - other people or circumstances can force a vampire inside. This is allowed because it is not the vampire that is doing it.
Further, once in, there is no obligation on the vampire to leave but if it does it cannot ...
It runs away from you at its normal speed and can return immediately
Dissonant Whispers (PHB p.235) states
On a failed save... and must immediately use its reaction, if available, to move as far as its speed allows away from you. The creature doesn't move into obviously dangerous ground...
So if the creature has its reaction available it uses its ...
You can't move, since you have zero movement left
You can release the target at any time, effectively changing your speed:
you can release the target whenever you like (no action required)
You will get your normal speed, but you won't get your movement back. In 5e "speed" is not equal "movement". For example, if your walking speed is ...
The rules do not indicate that the thorn whip spell uses a grapple (which the weird would be immune to). The water weird has no immunity to the effect of thorn whip. Very clever use of a spell to defeat a creature.
There are two ways to interpret this feature.
As a psychological obstacle. The vampire is incapable of making the decision to walk through the door unless invited. Forcing the vampire against their will would not affect this.
However, being forced to act against their nature might cause the vampire some distress, maybe even a strong urge to leave because ...
It's out of place in 4e, but 5e is a different game and it's not out of place in any way. You're not missing a rule, just importing expectations into the game that aren't part of it.
To avoid being pushed off cliffs or onto spikes in 5e, you do what people do: stay far away from cliff edges, pits full of impaling spikes, and other lethal hazards. ...
No, you can't provoke opportunity attacks this way. From the Player's Basic Rules, page 74:
You also don’t provoke an
opportunity attack when you teleport or when someone
or something moves you without using your movement,
action, or reaction. For example, you don’t provoke an
opportunity attack if an explosion hurls you out of a foe’s
reach or ...
From page 74 of the Basic Rules (also PHB p.195, or this SRD site):
[...] You can avoid provoking an opportunity attack by taking the Disengage action. You also don’t provoke an opportunity attack when you teleport or when someone or something moves you without using your movement, action, or reaction. For example, you don’t provoke ...
Ask your DM
This is not explicitly specified in the description of the spell, or the rules. It will depend on how your DM interpret the spell description if you do a 10-ft pull and a hole is between the caster and target.
What I would do: resolve the spell as up to 10-ft pull, regardless of terrain. If after resolving the target ends up on a tile with a hole,...
Movement does not reduce your speed.
The way Speed works in D&D 5e is as follows:
Every character and monster has a speed, which is the distance in feet that the character or monster can walk in 1 round.
Some creatures and characters additionally have a flying speed, which is how far they can fly in 1 round.
After moving its speed on a turn, a creature ...
Yes, you can generally shove your way out of a grapple
If a grappler can't reach their target, the grapple ends. If you shove someone 5' away, they won't be able to reach you anymore and the grapple will end. However, if their reach is larger than 5' they may be able to maintain the grapple on you (e.g. larger creatures).
I'm not aware of any rules RAW ...
Bets ends her turn in Anne's space
The first step of the solution is straightforward out of the PHB, on page 191:
Whether a creature is a friend or an enemy, you can’t willingly end your move in its space.
From earlier on that page, it's worth noting that Anne's space was difficult terrain for Bets, but that doesn't really matter now that she's stuck. ...
No, they can not enter.
The text for Forbiddance plainly states
The vampire can't enter a residence without an invitation from one of the occupants.
It doesn't use won't, it uses can't.
As in is not able to pass through the threshold. Someone can try and force them through, but they simply can't cross.
Your table may wish to allow an entry like this, and ...
PCs have no reason to move during combat unless you give them one
In my game experiences, I have seen very little movement by creatures during combat that wasn't forced upon them. There really isn't any incentive to change position (mostly because moving away/out of reach generates Opportunity Attacks.)
What you need to consider are environmental or other ...
Dissonant Whispers kind of does this already
Having recently played a bard in an extended campaign, I got a lot of mileage out of Dissonant Whispers, which uniquely forces movement that provokes opportunity attacks:
On a failed save, it takes 3d6 psychic damage and must immediately use its reaction, if available, to move as far as its speed allows away ...
Bets and Anne are in the same space.
PHB 191 states, (emphasis added)
Whether a creature is a friend or an enemy, you can’t willingly end your move in its space.
However, Bets did not willingly end her move--she was forced to by the opportunity attack. Since the rule forbidding overlapping spaces only refers to willing movement, it's valid for Bets to ...
No, pushing distance does not interact with difficult terrain at all
Difficult terrain states:
Every foot of movement in difficult terrain costs 1 extra foot.
However, pushing does not involve the spending of movement. The Open Hand technique says:
If it fails [a strength saving throw], you can push it up to 15 feet away from you.
The pushed creature ...
Yes, they can be moved
The effects you describe do not force the creature to move on its own, but impose an outside force and push it (pulling would work similarly to pushing). These are two separate kinds of "forced movement", the former usually involving mind control or fear effects and the latter involving physical forces, whether summoned, evoked or ...
The pull effect of Thorn Whip is contingent on a successful melee spell attack against a creature who is Large-sized or smaller.
If the attack hits, the creature takes 1d6 piercing damage, and if the creature is Large or smaller, you pull the creature...
If both conditions are true (the attack hits and the creature is no larger than Large-sized), ...
A creature pushing themselves goes nowhere.
Firstly, to move past concerns about whether this situation can happen: a monster can usually hit itself with its own attacks, by MM1 or 3 rules. They're inside their own range, and their powers usually target "one creature", which includes themselves. Let's assume a creature has successfully targeted itself with ...
Nothing special happens by RAW
There are no official rules describing being on or off a map in 4E. Squares, and what might be in them, are defined as game elements, but maps are not.
Technically, DMs that allow movement off map that looks like it should work (e.g. continuing along a forest path) are playing by RAW. If you can move to a location, and it ...
The spell does what it says it does, and the condition (Grappled) does what it says it does. Victor is flung 10'.
The spell moves Victor 10'. Clear enough. Unless something would stop that movement.
The condition doesn't cause Victor to be immobile, it reduces his speed to 0'. He's not nailed to the floor or encased in carbonite, it's just hard for him to ...
Yes, Bigby's hand can move in any direction even while grappling
Jeremy Crawford has clarified:
Q: is Bigby's Hand actually flying e.g. is it's movement speed = flying speed? The spell doesn't seem to describe it as neither "walking" nor "flying"
A: Bigby's hand doesn't have a speed. As the spellcaster, you can
magically move the hand in ...
Spells do what they say. The spell doesn't say they take damage if they cannot move 10 feet so they don't.
This is in line with falling damage as no damage is taken for falls less than 10 feet. Now, if you use such a spell to push them off a cliff ...
As written, this doesn't trigger opportunity attacks.
Since the spell doesn't use the target's movement, action or reaction, it won't provoke opportunity ...
Thanks to @Szega for the link to the related question: Is the Moonbeam spell amazing, or are we doing it wrong?
From the Sage Advice rules answers column from April 2016 (bold for emphasis added):
Reading the description of any of those spells, you might wonder
whether a creature is considered to be entering the spell’s area of
effect if the area is ...
You don't have to push
The wording on Repelling Blast is (emphasis mine):
When you hit a creature with eldritch blast, you can push
the creature up to 10 feet away from you in a straight line.
--- Player's Handbook, p. 111
The can here functions as an optional, meaning you are free not to do it. If that word had been omitted you would have no ...
Yes, you can shove an ally
The rules for shoving say
Using the Attack action, you can make a special melee attack to shove a creature ... The target must be no more than one size larger than you and must be within your reach. (PHB, p. 195)
There is nothing here to suggest that the target must explicitly be an enemy. Your ally is a creature, so you ...
It means you cannot move the target upwards.
"Horizontal" doesn't have any special definition, so we're expected to go with the literal - in absolute terms, in reference to the world around them. With that assumption, the intention of that word used there is apparent - it's so you cannot use the swarm to lift an enemy 15 feet into the air and drop ...