It's more accurate to say that there is always an OBND record on any NPC, and when I say "Skyrim.esm does not provide OBND" I mean that the record values are all zero for: X1, Y1, Z1, X2, Y2, Z2. Then, a later package (such as HearthFires.esm in my above example) modifies the record to provide other values. Edit: Also, what I mean with the bulleted list is that all cases are found, in different combinations: ones that are possible! :D. The two most common cases are: Skyrim.esm provides OBNDLater DLC keeps the OBND data if it edits the NPC record Skyrim.esm doesn't provide OBNDA DLC .esm does provide OBNDA mod that has Skyrim.esm as master (but doesn't have DLC as master) pulls in the all-zero OBND data set from Skyrim.esm, overwriting the change that DLC made. The most common values are: -22, -14, 0, 22, 14, 128. That seems to be a default across NPC of any size or age. However, there is variation. GulumEi "Gulum-Ei" [NPC_:00013284] is -24, -24, 0, 24, 24, 128. He's an Argonian. I'm currently taking the set to be related to bounding volume of the actor model, and that's part of why I'm interested in the effect of it. That it's provided at all means it has a use (at very least it had an intended use). If that use is involved in simplifying some actor model related calculations, then it's possible that the game engine does extra work on every actor that doesn't provide that data set in its record. It's also worth noting that 128 units on Z matches Bethesda's actor height assumption in level design. Amusingly, child bounding volumes are six feet tall by that measure. Also worth noting that this can't be related to child adoption, unless adult male Nord Bandits are adoptable. :D