I believe it is called tactics. If its combat.Why do people keep doing this?
Yeah. It's often what I do - but then see incredibly bad rolls.Red slaad squeezes into the gap the makes up to 3 grapple attempts on someone it can reach (doesn’t suffer disadvantage) then pulls the lead character back into the room.
The blue slaad munches away on the grappled lead character. If the lead character can’t be grappled in a round or two, the red slaad backs away so it’s regeneration kicks in while the blue slaad has a go.
That would be my approach. Assuming there’s no obvious way round to the side.
It doesn't work that well. When the door is closed, both sides just sit there looking at it. When it opens, often you just have to reroll initiative.Reminder, creatures can close doors too. They could easily close the door and ready to attack as soon as it opens.
Realism. In real life, 5 foot is quite a wide passage.Why do people keep doing this?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.