rules for occupying same space?

[Dingleberry]

Are there any 3.5 rules out there that address similarly-sized creatures occupying the same space in combat?

 

[Herzog]

(from memory, so I may be mistaken
1. You can't. If you end your turn in a space occupied by another creature outside of your doing, you are forced out to the nearest free space. You will also be prone. You cannot willingly end your turn in the same space as another creature to force this.
2. When you are grappling, you ARE considered to occupy the same space.
3. Creatures that differ two size categories or more can occupy the same space.
4. There is a group-tactics feat (I think in Complete Warrior) that allows Small or smaller creatures to occupy the same 5' square.

 

[billd91]

If the structure of the map space forces characters to overlap (which sometimes happens with the large half-ogre in the party), rather than force on of them prone, I allow them to overlap but enforce squeezing penalties to their defense and offense. That's my take on the cases where being forced out is impossible and being knocked prone is unreasonable.

 

[Man in the Funny Hat]

Are there any 3.5 rules out there that address similarly-sized creatures occupying the same space in combat?

The 3.5 rules by intent do not allow similar-sized creatures to occupy the same space. They certainly do not acknowledge that it might happen anyway despite intent and thus do not provide rules for the eventuality. You either create house rules or you sacrifice your suspension of disbelief to the convenience of the rules.

 

[Dingleberry]

If the structure of the map space forces characters to overlap (which sometimes happens with the large half-ogre in the party), rather than force on of them prone, I allow them to overlap but enforce squeezing penalties to their defense and offense. That's my take on the cases where being forced out is impossible and being knocked prone is unreasonable.

This may get me bumped to the House Rules forum, but can I ask what you used for those squeezing penalties? I was planning to create a "crowded" condition that imposed a penalty to AC and attack rolls, with the degree of penalty tied to the size of the "crowded" creatures, and maybe also treated each one as cover for the other for ranged attacks by enemies. I thought denying Dex bonus to AC would be too big of an impact. Obviously, another downside is that it would allow area attacks to affect more than their usual number of targets. Or maybe keep it simpler and just treat creatures sharing a space as "entangled," plus the cover thing. Thoughts?

 

[billd91]

This may get me bumped to the House Rules forum, but can I ask what you used for those squeezing penalties?

I just grabbed them from the SRD, minus the movement penalty.
"...while squeezed in a narrow space you take a –4 penalty on attack rolls and a –4 penalty to AC."

I figured that would be enough to get PCs to spread out when they can. Plus, I usually only allow it if the map kind of forces it to happen.

 

[Keith Robinson]

There seems to be some confusion about whther this is a rules question. The 3.5 rule set clearly defines rules for this. Below are the 3.5 rules (quoted from the PHB with page reference) for occupying or passing through an already occupied square:

Moving through a Square:

Friend: You can move through a square occupied by a friendly character, unless you are charging...

Opponent: You can't move through a square occupied by an opponent, unless the opponent is helpless... You can move through a square occupied by a helpless opponent without penalty. The DM may rule that some creatures, such as an enormous dragon, present an obstacle even when helpless. In such cases, each square you move through costs 2 squares.

Ending Your Movement: You can't end your movement in the same square as another creature unless it is helpless.

Overrun: During your movement... you can attempt to move through a square occupied by an opponent (My Edit: please note that the phb also says that you can use overrun as part of a charge, but this was errata'd to "It’s not possible to overrun as part of a charge.")

Tumbling: A trained character can attempt to tumble through a square occupied by an opponent...

Very Small Creature: A Fine, Diminutive, or Tiny creature can move into or through an occupied square. The creature provokes attacks of opportunity when doing so.

Square Occupied by Creature Three sizes Larger or Smaller: Any creature can move through a square occupied by a creature three size categories larger than it is. A gnome (small), for example, can run between the legs of a cloud giant (Huge).

A big creature can move through a square occupied by a creature three size categories smaller than it is. A cloud giant, for example, can step over a gnome.

Designated Exceptions: Some creatures break the above rules. For example, a gelatinous cube fills the squares it occupies to a height of 15 feet. A creature can't move through a square occupied by the cube, even with the Tumble skill or similiar special abilities. (My edit: please note that the gelatinous cube was errata'd to a 10 feet (large) cube)

Also...

Accidentally Ending Movement in an Illegal Space: Sometimes a character ends its movement while moving through a space where it's not allowed to stop. For example, you might incur an attack of opportunity from a monk while moving through a friend's square and become stunned. When that happens, put your miniature in the last legal position you occupied, or the closest legal position, if there's a legal position that's closer.

I am not aware (in 3.5) of any rule which says ending your movement in an occupied square means you are prone (though maybe I've just missed them?).

As Herzog mentions, the only other way (that I'm aware of by the core) is to initiate a grapple.

HTH

 

[Herzog]

I was under the impression that ending your turn in an illegal space would force you to a legal space, and that you would then be prone in that space.
However, now that you question that assumption, I can't seem to find that particular rule (other than the forced placement you already quoted).

I might be confused with 4.0

 

[Jhaelen]

I was under the impression that ending your turn in an illegal space would force you to a legal space, and that you would then be prone in that space.

You may have been thinking about Bullrush:

If you fail to beat the defender’s Strength check result, you move 5 feet straight back to where you were before you moved into his space. If that space is occupied, you fall prone in that space.

or Overrun:

If you fail and are knocked prone in turn, you have to move 5 feet back the way you came and fall prone, ending your movement there. If you fail but are not knocked prone, you have to move 5 feet back the way you came, ending your movement there. If that square is occupied, you fall prone in that square.

Then there's Trample:

A trampling creature that accidentally ends its movement in an illegal space returns to the last legal position it occupied, or the closest legal position, if there’s a legal position that’s closer.

 

[risner]

Are there any 3.5 rules out there that address similarly-sized creatures occupying the same space in combat?

DMG p29 (or close to page 29) covers multi in same square.

2 size cat difference allow only has as many in the same square.
3 size cat difference = gravy