can someone explain the multiple damage type 'bug' to me?

[rkanodia]

Hi all. In PnP D&D, weapons with multiple damage types are generally treated as using the most advantageous type for a given target. However, I see lots of posts on this board talking about how multiple-type weapons (such as halberd and morningstar) are bugged, acting in the LEAST advantageous way. I wanted to try this out, so I tried using three different weapons against ordinary skeletons. Those weapons were:

Masterwork Iron Morningstar (B/P)
Masterwork Iron Mace (B)
Masterwork Iron Dagger (P)

Damage Immunity protected the skeletons against 5 points of damage from each blow with the dagger. With the mace and the morningstar, the skeletons took full damage. Can someone explain to me what I'm missing?

[JesterOI]

I've done testing myself.
From what I have seen, Morningstar's act predominantly as bludgeoning weapons. They skip peirce resist.

Longswords and [censored] Swords will suffer from both slashing or peircing resists. Which is why I don't use them.

My 18 fighter is a general weapon user, as such I have only taken the improved crit feats for scim, rapier, and warhammer, what I consider the best single handers from each single physical damage type.

Personally I try to avoid using any dual damage type weapons.

[rkanodia]

Hmm, I just did some testing on a Forest Giant and it looks like you're right about the Morningstars. Thanks.