home field advantage?

[LightPhoenix]

there are already lots of balancing factors in combat, such as being underwater or wall climbing or flying or cover...but should there be a home field advantage?

wouldn't it make a neat feat for bad guys (maybe p.c.'s)? +2(+4?) to all attacks on your home turf. maybe +2 on a big area OR +4 in a building or a tree or whatever the home base is.

what do you think? has this been done? can it be done well?

I believe in Speulchave's Storyhour, the druid Nwn has a grove in which all his spells are Maximized as the Maximize Spell feat.