I like to tinker with the 4th Edition rules, which means I’m always in danger of breaking them. Luckily Rory has an infallible ability to discover broken abilities, which means that I can always pass an idea to him and he can instantly tell me the massively game-breaking implications of my proposed new mechanic.
When Rory’s not around, I use a rubric called the “Is it more powerful than Weapon Expertise, Staff of Ruin or Iron Armbands of Power?”
This feat and these two items are so good that they make it hard for competing feats/items, no matter how cool they are, to get chosen.
Weapon Expertise
It’s pretty well agreed that the Weapon Expertise and similar feats were introduced as a math fix for runaway monster defenses, and that D&D R&D intends that everyone take the feat. Luckily, except at very early levels, everyone has lots of feat slots, so you can take other, more flavorful feats in addition without feeling like you are shooting yourself in the feat. Still, under normal (non-math-fix) circumstances, I’d say that any feat that was a must-have for all characters was clearly overpowered.
Staff of Ruin
Staff of Ruin is a different matter. Every staff-using character should probably use this item. That means that every other staff is obsolete, and can only be taken by perverse players who like to play intentionally suboptimal characters – the half-orc bards among us. Most implements have daily powers, but Staff of Ruin reliably does lots of extra damage on every hit. A +1 staff of ruin that does an extra 1 item damage isn’t so unbalanced, but a +5 staff of ruin, doing 5 enhancement and 5 item damage on every hit, competes well even with many +6 magic staffs.
Not convinced? A staff of ruin is level 23. How much damage is a level 23 wizard with a +5 staff doing with encounter powers? 4d6+Int+5, or around 25 damage to each opponent, possibly with some status effect. Let’s be generous and say that with the other hit effects, a wizard encounter power is worth double its straight damage, or 50 damage. A wizard probably hits each opponent about 60% of the time, so that’s a damage expectation of 30 HP per opponent.
A +6 magic staff adds 1 to damage – let’s call it 51 damage now – and increases the chance to hit to 65%, which translates to an expectation of another 3 or so damage per opponent. So for encounter powers, with generously assessed damage, a staff +6 is worth 4 points of damage more than a staff +5. A staff of ruin +5 beats that by a point.
You could argue that a staff +6 may lose on normal hits, but it has one extra critical die. The average critical damage for a staff +6 is 6d6, or 21 extra damage. A staff of ruin, for some reason, uses d10s for critical damage, so on a critical hit it does 5d10, or 27.5 damage – beating the staff +6 by more than 6 points of damage. (Why? wasn’t Staff of Ruin already considered good enough?)
OK, so a staff of ruin arguably beats a staff +6, but I can see that my arguments are not incontestible. I’m on safer ground when I say that the staff of ruin beats any other +5 staff. Most of the staffs only have daily powers. Comparing item properties to item daily powers is difficult, but let’s ballpark how many times a wizard will score a hit in the average day. Using conservative estimates, let’s say that the average 4e battle lasts 7 rounds; the wizard, using a mix of single-opponent and multi-opponent attacks, hits one opponent during 3/4 of the rounds; and that there are 3 encounters in the average day. That’s a little more than 15 hits per day. That feels very low to me, but even with these numbers, the Staff of Ruin is contributing 79 damage, and that’s the number that the +5 staff daily powers need to compete against. Let’s see what else we have: the Quickening Staff lets you use an extra at-will attack once daily, not nearly worth 79 damage… Staff of the Sunburst does 10 damage to enemies within 5 squares: situationally could beat 79 damage if your wizard likes to mix it up and your DM likes to throw 8 non-minion opponents at the group once every day… Staff of Gathering gives you +2 to hit and +10 to damage to one attack… Staff of Draconic Power does 3d8 in close burst 1… Staff of Storms does 3d8 in close blast 3. All of these staffs have non-damage components too, but it’s still hard to imagine taking any of them. They’re all higher-level staffs than the Staff of Ruin.
Now let’s talk about what staffs have cooler flavor than the Staff of Ruin. The Feyswarm Staff surrounds its target with magical stinging insects. The Staff of Winter freezes targets in their place. The Staff of Wind conjures a gust that sends people flying. All of these feel more wizardy than the generic Staff of Extra Damage. But as a player, if I put any of them on my magic-item wishlist, I’d do so knowing that I was sacrificing character effectiveness for character flavor.
Iron Armbands of Power
This is the same deal as the Staff of Ruin but for melee characters. It grants all melee attacks +2 item bonus damage at heroic level, +4 at paragon, and +6 at epic. Pretty much the same calculations apply here as for the Staff of Ruin, but in the less competitive arms slot, so it’s even more the obvious winner.
The +6 Iron Armbands are level 26, so I’ll take a look at the levels 27-30 arm-slot items to see if any higher-level bracers come anywhere close. Best in show is Bloodsoaked Bracers, the only level 30 bracers currently in the game, which have a daily power that gives you a power bonus of +15 to damage while you are bloodied. That’s more than double the damage bonus of the Iron Armbands. Of course, you can only use them while bloodied, which is probably less than half the time; and you can only use them once per day, so they only compete with the Armbands if you expect an average of one encounter per day. Runner up might be Bracers of Defense, level 27, which reduces damage against you by 30 once per day. That’s the same amount of damage as you’re doing in 5 hits with the Iron Armbands, so again, unless you fight one encounter per day, you’re better off passing. Booby prize goes to the Skull Bracers, level 27: once per day, do 3d10, or average 16.5, extra damage. If your melee character gets an average of 2 or less hits per day, it’s a good deal.
Conclusion
Apart from “Wizards: Don’t make any more items like this!” I’d say my takeaway message is: if you’re looking to make some custom feats and items for your campaign, use these as a yardstick. If your creation is as powerful as these, then immediately throw it away. If your creation is more than half as powerful as these, I’d seriously consider nerfing it. In fact, halving the benefit of these items isn’t a bad start: Weapon Expertise can’t be fixed, because +1/+1/+1 attack bonus per tier, instead of +1/+2/+3, is probably still a dominant feat; but a Staff of Ruin and Iron Armbands that do +1/+2/+3 bonus item damage at the three tiers might actually be balanced. Or close. Well, only a little overpowered.
My second conclusion is: if you’re looking to start a “banned game elements” list for 4e, you could start with these three. They’re surprising outliers in what is, on the whole, a pretty balanced edition.