A halfling and a human are blocking a group of winter wolves (size Large) on a 10-foot-wide ledge. Can the wolf move past the blockers by squeezing or overrunning:
- Can the wolves just squeeze through the halfling's space since it is
two sizes smaller? Could they do this at 1/2 speed or 1/4 speed? - Do the wolves need/get to overrun both at advantage, since they only
take up 2 squares and winter wolves take up 4?
(We're playing G2, "The Glacial Rift of the Frost Giant Jarl", the second module in Against the Giants from the Tales from the Yawning Portal book.)
Best Answer
It's not moving past, it's moving through at 3 feet for every 1 foot
It's a bit weird to imagine, but you've basically described that there is a Small and Medium creature 'blocking' a 10' wide space.
The rules around moving through other creatures are found in Chapter 9 of the PHB under Movement and Position
So, while each creature controls a 5' space, there are specific rules about moving through. And if the space that a creature wants to get to means you have to go into another creature's space, then the above rules apply.
In your case, you've got a medium and a small creature holding the line. As they are hostile to the winter wolves, the spaces can not be moved through unless there is a size different of two sizes.
The medium creature does not allow movement through, as they are just one size larger. But the small creature does allow movement through, as they are two sizes smaller.
Passing through the line
If the winter wolf wants to get 'through' the line, they must pass through the space of the small creature and treat the movement as difficult terrain. However, that space is too small for them, so now the squeezing rules come in. Those are found in the same section and state:
This means that the winter wolf must treat passing through the space as difficult terrain and are being squeezed. So each foot of movement actually costs 3 feet of movement (an extra foot for difficult terrain and an extra foot for squeezing through.)
Also note that if they leave the reach of either creature, the winter wolves will also trigger an opportunity attack.
A second option is in the DMG: Overrun
Chapter 9 of the DMG also covers some additional optional actions. If the table/DM decides, there is another option for moving through hostile creatures which opens it up beyond the above and ignores the size differential requirements in exchange for additional mechanics: