Always snap to grid

From Unreal Wiki, The Unreal Engine Documentation Site

This mutator makes the entire level behave as if it was on the moon. A side effect of this mutator is all jump boots are removed.

[edit] Methods Inherited From Mutator (UT)

bool CheckReplacement (Actor (UT) Other, out byte bSuperRelevant) 

This function returns false for every instance of UT_JumpBoots encountered removing them from the game. For all objects of type ZoneInfo (UT) the function sets the ZoneGravity vector to (0,0,-200). Oddly enough the mutator doesn't set the bGravityZone property of the ZoneInfo (UT) class.