The issue here is scope. There is literally hundreds if not thousands of items that would need to be rebalanced. Invariably after trying to go item by item, things will be missed, values may get fat fingered, and so forth making a mess of things. So this makes this a bit of a fantasy and a pipe dream.
The other suggestion of server settings is also problematic. It doesn’t address the issue, it tones it down. So if the server setting is set at 50% PC damage to PCs for example. An OP weapon does 50% less damage, but so does everything else. The OP weapon is still OP. It may not one-shot anymore, but it is still killing in far less hits than its alternatives.
There is another way however.
Instead of using the stats on a weapon or armor, or rather making new stats on all weapons and armors. The system determines your ability (damage reduction, damage, armor penetration specifically) based on the following criteria:
Tier (Stone, Iron, Steel, and Hardened Steel*)
Type (Light, Medium, and Heavy armor, or type of weapon like Dagger, Broadsword, Mace, etc.)
*Using anything above Hardened Steel defaults to hardened steel.
Now this is going to irritate some because they are going to be clamoring about what is the point of getting anything above hardened steel. Well… first… that’s PVE content. So PVE for PVEers, and PVPers should be focused on PVP right? And second, you still get the other effects that those items give, its only damage, armor pen, and damage reduction that is standardized. So there will still be ‘better’ equipment outside of Hardened Steel.
If needed those effects on certain weapons and armors could be turned off or mitigated if needed based on the setting of the server. So if PVP is enabled, stuff like the Lifeblood Spear or other things that aren’t bad in PVE, would be ‘nerfed’ only on servers with PVP on. So yes the PVE will be nerfed on PVP servers. But a PVP server is for PVP and not PVE (probably could make this a separate setting so private servers who use PVP on PVE type for certain reasons can still do so, they do exist).
But if you want true balance, this is how you go about doing it. This way they only need to balance pretty much one tier (Hardened Steel, whereas the others are just slightly weaker) of weapons and balance them to each other selecting a single value to rule them all. Which means in PVP you won’t be likely to use the best ‘meta’ as much as you would the weapon type and armor you like.
There will still be meta builds based on stats on armors of course, there’s no getting around that. But at least there will be more variety of weapon types. But removing the disparity. As well as any effects on PVE.
This system should be relatively easy to implement comparatively to pretty much any other alternative. Requiring a reference to a much smaller table when referencing the values of damage, armor pen, and damage reduction when a PC is attacked by another PC.
And when a rebalance is needed, the table values are altered. Thus avoiding any sort of changes affect PVE as it would be entirely divorced. And we also avoid stat and gear escalation going forward in PVP. When new content is added, new dungeons, and all that, no new equipment will ever be OP in PVP by the nature of being capped. The effects are the only thing that will need to be looked at, and can easily be adjusted by the aforementioned setting mentioned earlier.
The downside is some people might see less incentive to get some higher tier equipment. I get that. And that is a side effect of this. But I believe that since this is a PVP oriented change, that disincentivizing PVE in a small way is acceptable. Making it a setting that PVP servers can opt into, will allow those running said servers to determine if PVP or PVE is more important.
But I suspect most PVP servers would elect to choose a more PVP oriented setting. PVPers would rather PVP more than PVE after all.