You're implying that the proper use of a longsword involves extending your arm all the way up, locking it out, and holding the sword tip as high as you can.Longsword, you say?
The vertical reach of a medium character per the Jump skill is 8 feet.
A longsword is 3 feet long.
Therefore, you cannot freely swing a longsword in an area with a 10' ceiling.
Therefore, the character will actively try to avoid swinging overhead, although they forget and/or be forced to in the heat of battle.
This can be worked in by changing the automatic miss from 1 to 1-3 with the entire range being a fumble range - whoops, I just clanged my longsword off the ceiling, my bad. Then you would need to also determine whether the longsword breaks based on its hardness in comparison to the ceiling and the strength of the character swinging it.
Casters, on the other hand, rarely suffer from these difficulties and can generally operate quite well in confined spaces.
The thought occurred to me that a fighter with a spiked chain or cleric with a longspear should not be able to use those weapons effectively in certain situations, such as if they were fighting in a 5x5 dungeon corridor, or in a doorway.
Casters, on the other hand, rarely suffer from these difficulties and can generally operate quite well in confined spaces.
Hmm...now that I think of it, fellow party members are something much harder to avoid hitting by mistake than static walls. How to reflect that in the game though?
It would make sense being able to use a shuriken while prone, but how about other throwing weapons? Darts, for instance, should be just as useable, I'd say.
Throwing knifes, axes, hammers - might be useable, but perhaps with a penalty.
But is the use of shuriken RAI, RAW, or Houseruled? I can't find it in the SRD, and don't have the time to go leafing through my books atm.