It's a well known fact in D&D that small rooms favour outnumbered parties, as the opposition cannot bring their full force to bear upon them. Larger rooms favour the outnumbering party, as they can surround their opponents.
When the monsters are outnumbered by the player characters, it might make sense for them to seek out a small rooms to fight in. However, this creates a situation where not all of the characters can fight effectively. The wizard's area spells, for example, have a very high chance of also damaging their friends.
Small rooms also limit the extent to which characters can manoeuvre, often creating static battle lines in which both sides simply basic attack each other until one side goes down.
How can I improve combats in small rooms such that players feel that their characters are not too hampered by them, while still retaining the tactical advantage they give to the outnumbered party?
I would like answers from people who have successfully run combats in smaller rooms.
- My party has six members.
- By small, I mean below around 25ft by 25ft (where one 'square' is 5ft).