Hriston
Dungeon Master of Middle-earth (He/him)
The reason no check is required for friendly spaces is that Bob the Fighter is keeping an eye out on everyone around him, you included, so when you enter his space he attempts to dance around you while you quickly move through it.
Now, what has been consistent in all of this is movement whether you are attempting to squeeze or running straight through, you are still moving. The key words fall into "breaking up your move" when you attack you are explicitly ENDING your movement in order to do something else (attack).
Now certainly if you are allowing a person to make some sort of check to occupy another's space, that's certainly an option, it's not by the RAW but it's an option. By the RAW, since you cannot squeeze through another's space and you cannot end your movement in another's space, you cannot STOP moving in their space to attack.
You don't need to stop moving or end your move to attack. In fact, quite the opposite is implied by the phrase "breaking up your move". Your move, i.e. the use of your speed, does not end when you attack. Rather, you may continue to use whatever part of your speed was unused before your attack was resolved. There is no need to imagine that this requires the character to come to a full stop, but even if it did, there is no prohibition that I can see on taking an action while in the space inhabited by an allied creature.
If you want to end your movement in the space of another, by RAW, you're going to have to potentially use a spell or play a halfling. Or of course, come up with a variant rule that allows your to do so.
Halflings are not allowed to willingly end their move in another's space any more than are other races. The benefit of Halfling Nimbleness is that it allows halflings to move through the spaces of enemies provided that they are one size larger. It doesn't allow halflings to end their turn there.
Personally, a feat like say "Back to Back Fighting" that would allow two players with the feat to occupy the same square while fighting, would be hella cool.
Agreed, but perhaps it wouldn't be necessary considering how easy it is for them to move through each others spaces, paying only the penalty for difficult terrain.