Heavy Armor made Lighter

[Shane_Leahy]

Couple of us got talking and had an interesting question.

If you make Heavy Armor out of Mithral, do you still need the Armor Proficiency (Heavy) to use it. This question came up because my wife is thinking of playing a Warmage (WotC Miniatures Handbook) and they get Armor Proficiency (Medium) with no Arcane Spell Failure.

The revelant rules are:

Mithral - DMG 284 -

Most mithral armors are one category lighter than normal for purposes of movement and other limitations (for example, whether a barbarian can use her fast movement ability while weating the armor or not). Heavy armors are treated as medium, and medium armors are treated as light, but light armors are still treated as light. Spell failure chances for armors and shields made from mithral are decreased by 10%, maximum Dexerity bonus is increased by 2, and armor check penalites are lessened by 3 (to a minimum of 0)

Non-Proficiency in Armor - PHB 122

A character who wears armor and/or uses a shield with which he or she is not proficient takes the armor's (and/or shield's) armor check penalty on attack rolls and on all Strength-based and Dexerity based ability and skill checks.

So my reasoning is:

Just because armor is made out of Mithral, it does NOT change the type of armor and one must still be proficient in said armor. The non proficient penalities would be lower due to the fact of the lower armor check penalites of Mithral armor but they are still there.

The other side was stating two things:
1) That it BECOMES medium armor so Armor Proficiency (Medium) is all that is required.
2) Then stated that the penalites associated with non proficiency are eliminated due to the "Other limitations" statement in the Mirthal section.

Of course as I am the DM, my ruling goes : but I wanted to hear what others had to say on the matter.

 

[gtJormungand]

So my reasoning is:

Just because armor is made out of Mithral, it does NOT change the type of armor and one must still be proficient in said armor. The non proficient penalities would be lower due to the fact of the lower armor check penalites of Mithral armor but they are still there.

This is the letter and spirit as far as I can tell for this rule. It's been mentioned before somewhere, I just don't remember where.

 

[Ulorian - Agent of Chaos]

The relevant rule is:

Most mithral armors are one category lighter than normal for purposes of movement and other limitations.

Mithral half-plate is still a heavy armour and requires the heavy armour proficiency to use. The side arguing against you is omitting the part of the rule I've italicized.

 

[Quirhid]

I think heavy armor is treated as medium... but it's still harder to move in a heavy armor than in a medium... so if heavy armor proficiency has enything to do with movement, I think you'll need a heavy armor proficiency. :\

It's up to you!

 

[Black Knight Irios]

As said before it still requires Armor Profiency(Heavy) because the wording of the Mithral Material indicates that the benefits of the lighter armorcategory apllies only to movement and other limitations, like the Barabarians Fast Movement ability or your base speed.

 

[Gort]

Well, isn't "you must have heavy armour proficiency to use without penalty" a "limitation" of heavy armour?

 

[shilsen]

Well, isn't "you must have heavy armour proficiency to use without penalty" a "limitation" of heavy armour?

Nope. It's a limitation of the poor idiot who doesn't have the proficiency