# Is there a balance problem with adapting Arcane Might properties to all weapons?

The Arcane Might magic weapon property from the Magic Item compendium says:

ARCANE MIGHT

Price: +1 bonus

Property: Bows (not crossbows)

Caster Level: 15th

Aura: Strong; (DC 22) transmutation

Activation: Swift (mental)

This elegant, supple bow has intricate runes carved along its length. You can channel the energy of your arcane spells through this bow to make the arrows fired from it more damaging.

As a swift action, you can sacrifice a pre-pared arcane spell from memory (or an unused spell slot if you are a spontaneous arcane caster). Doing so grants a bonus equal to the sacrificed spell’s level on the next damage roll you make with the bow that turn.

Prerequisites: Craft Magic Arms and Armor, greater magic weapon.

Cost to Create: Varies

Is there a balance problem with applying this property to other weapons? To crossbows? To melee weapons?

I understand that the "not crossbows" is there to prevent very low-strength casters from using this. However, this shouldn't be an issue with melee weapons. Is there any reason to discourage this?

-
I really am curious why they thought this would be a problem for crossbows. I get the impression they had a blanket policy of just making something underpowered if they didn't have the time/resources to balance it properly. (I even vaugely recall Mearls mentioning something about this; it was with regards to how he ignored it for the Bo9s. :) ) – starwed Jun 10 '13 at 19:07
@starwed I'd really love to see that quote if you can find it! – KRyan Jun 10 '13 at 19:22
@KRyan I looked, but there's a post-4e blog he did about game balance that makes googling for anything he said earlier hard to find. – starwed Jun 10 '13 at 20:07

Realistically, I cannot imagine any situation where I’d want to sacrifice a spell and a swift action for just +spell_level damage. It’s just not enough damage. At the cost of a +1-equivalent? Vastly overpriced.
Compare the Arcane Strike feat (Complete Warrior). It’s costlier (feats are worth more than a +1-equivalent), and it’s still not great, but you get +spell_level to attack (more valuable than damage), plus (spell_level)d4 damage (on average, 2½× what arcane might offers). And Arcane Strike is a free action.