Does treating a weapon as "light" mean it cannot benefit from feats like power attack?

Question

An elven rogue with weapon finesse (PH p. 102), weapon focus: longsword (PH p. 102), and power attack (PH p. 98) is about to take her 9th character level, becoming a level 9 rogue and gaining, among other things, another feat to choose.

For this level, she plans to take the feat graceful edge (Dungeon Magazine, issue #128, p. 44), applying its benefits to her longsword. One of graceful edge's benefits is that "[i]f you do not wield a shield or weapon in your off-hand, [then] you treat your chosen weapon as a light weapon."

Part of power attack says "[y]ou can’t add the bonus from Power Attack to the damage dealt with a light weapon[.]"

I cannot find anything that suggests "treating" a weapon as light means it is or isn't light. Is this weapon still one-handed? Or is it now "light," and ineligible to benefit from power attack?

Answer 1

The rules set is full of exceptions. A thing is this until I acquire some feat or ability or situation or set of circumstances that makes what's normally this now treated as that.

I cannot find anything that suggests "treating" a weapon as light means it is or isn't light. Is this weapon still one-handed? Or is it now "light," and ineligible to benefit from power attack?

When "treat as" or "treated as" is used, it generally means for all intents and purposes, unless it specifies a specific set of circumstances for which it is "treated as".

For example, under the ranger's combat style ability,

If the ranger selects archery, he is treated as having the Rapid Shot feat, even if he does not have the normal prerequisites for that feat.

As there are no circumstances listed, effectively the ranger now has the Rapid Shot feat.

Also, when armor is created from mithral,

Most mithral armors are one category lighter than normal for purposes of movement and other limitations. Heavy armors are treated as medium, and medium armors are treated as light, but light armors are still treated as light.

Heavy and medium mithral armor are treated as one category lighter than normal for purposes of movement and other limitations. "Other limitations" is pretty broad though.

However, if you look at the monk entry,

Her unarmed attacks are treated as magic weapons for the purpose of dealing damage to creatures with damage reduction.

In this case, there are specific circumstances listed. Otherwise, they are not treated as magic weapons. They aren't detectable as magic, nor do they use an item slot, for example.

In the case of graceful edge,

If you do not wield a shield or weapon in your off-hand, you treat your chosen weapon as a light weapon.

To avoid confusion, I'm going to avoid the fact that off-hand only applies to two-weapon fighting and assume this just means you're a bipdeal creature and "your hand not armed with your chosen weapon".

In this case, you would not be able to use Power Attack any time you do not wield a shield or weapon in your off-hand, because you treat your chosen weapon as light, gaining the Weapon Finesse benefit. However, you could wield your chosen weapon with two hands, or pick up a shield or other weapon in your other hand and it would revert to being a one-handed slashing weapon, qualifying for Power Attack, but not Weapon Finesse.

As worded, you cannot use the two together (Weapon Finesse and Power Attack via Graceful Edge), other than with DM fiat. Having said that, this DM would probably allow it.

Answer 2

The longsword weapon table entry clearly indicates that it is not a light weapon. A class feature which allows you to count a weapon as light does not change the weapon table entry, nor any quality of the weapon; it is rather a special exception which adds an ability to the character, as opposed to something which affects the weapon directly.

Compare to the Mithral special materials entry in the DMG. Mithral changes the category of armor, but not weapons. The language used is "...are one category lighter than normal..." for the armor.

Had it been intended to actually change the weapon weight category for all purposes, then language similar to that of mithral would have been used. Instead, the language "counts as" was used.

Comparing to the powerful build trait, it is sadly noted that this language is more precise in revealed intention than the phrase "counts as light"... and it also doesn't actually use the phrase "counts as" anywhere in the text. Instead, it directly and clearly states that the character is treated as one size category larger and furthermore adds when it would be advantageous which effectively places the interpretation in the player's hands. It is worth noting that "treats as" and "counts as", while not exactly the same, are synonymous in meaning.

Had this Powerful Build language matched the "counts as light weapon" language exactly, then it would have clinched the argument for certain. Despite this, the similarities are worth examining, and lead this one to believe that "counts as" should be treated in the same manner as the powerful build feature, and not as the language in the mithral description.

It is further worth noting that a class feature which affects a weapon (such as counting it as a light weapon) only works for the one character, no one else; which is further implication towards the weapon not actually being light. Should another character, NPC, or monster pick up the exact same weapon, it is not a light weapon. This again implies an additive option, rather than a forced changed.

As such, yes, you should be able to use both effects.

Answer 3

It's now light

The feat doesn't say you may treat the weapon as light, but that you do This means you can no longer add damage from power attack, and potentially means you can no longer deal 1-1/2 times STR damage when choosing to wield such a weapon in 2 hands. It also means pricing that's based on weapon categories is different for you, you find it harder to disarm enemies, etc. You treat that chosen weapon type as a light for all purposes, except when you choose to wield a weapon or shield in your off hand.