Backporting PF2 Magic Weapons

[Auroch]

I'd like the opinions of GMs and the efforts of CharOp munchkins on a rules tweak I'm considering.

The Pathfinder 2 playtest has many things wrong with it, and so my players declined to play the playtest, much less an ongoing game (I was reserving judgment but find the decision understandable). However, there are a couple bits and pieces I want to backport to a Pathfinder/3.5 game. The one that seems the most risky to me, but also potentially the most worthwhile, is how a +1 weapon works. Rather than giving +1 to attack and damage rolls, they grant +1 to attack and +1 die to damage. So if you take a longsword (1d8, 19-20/x2) and make it a +1 longsword, it now deals 2d8, 19-20/x2 on a hit. (The extra die is multiplied by crits, as normal.)

This seems good in that it tilts the balance of power toward weapon-attackers and away from spellcasters, but I expect it will have unintended consequences. So, how is this likely to warp the game for my players?

[Psyren]

Bringing that back to P1 means anything that affects die size will get boosted considerably, such as actual and effective size increases on the wielder. It'll also considerably boost effects like Vital Strike. None of those are really deal-breakers though, especially past lower levels.

[MrCharisma]

It'll make Enlarge Person a much better spell. It also makes Lead Blades better (although funnily enough it makes the Impact Weapon worse, since it does pretty much the same as +1 enhancement, but costs +2 ... until later levels anyway).

I was thinking a Vital Strike Warpriest would be crazy:
Scimitar = 1d6/18-20X2
6th level warpriest = 1d8/18-20X2
+1 weapon would be 2d8/18-20X2
Using Focus Weapon (for another +1) = 3d8/18-20X2
Enlarge Person = 6d6/18-20X2
Vital Strike brings it to 12d6/18-20X1.5(ish) at level 6.

But then I thought about a Magus and realised they'd have more stuff (they ALWAYS have their weapons enhanced, and can have them at +5 by level 9 pretty easily).
9th level bladebound magus has 3 attacks with 5d6/15-20X2 without expending any energy. Haste adds an extra attack, Enlarge person turns those d6's into d8's. If you CAN get Impact on it as well it turns those d8's into 2d6's.

My thoughts are that this will advantage the Gish classes more (especially at lower level), but that it will advantage martial classes generally.

It will also change the balance of a lot of the enchantments you can put on weapons - Why go flaming when the enhancement bonus is strictly better?

[Auroch]

Impact Weapon seems like it gets significantly better, actually. It increases the size category of your damage dice, which grants +N average damage, where N is your enhancement bonus+1, instead of +1 with standard rules.

I'm thinking I might also make the price increase of magical properties be tracked separately for enhancement bonus and special properties, so that getting fancy weapons that do stuff has a lower opportunity cost.

Someone offline pointed out that this makes TWF fall even further behind a two-handed weapon, which is not ideal. I don't see any way to patch that, though.

Vital Strike I already considered; it would be errataed to only add one die of damage, but allow that to be doubled to two on a crit. Same for Improved/Greater Vital Strike; those would grant +2dX/+3dX, respectively, but would double on crit. That doesn't make them no-brainers, but they stay very viable feat choices.

[MrCharisma]

The reason I thought Impact would be worse is because it does the same thing (almost) but doesn't give the bonus to hit.

Let's say you've got a +3 scimitar: That's 4d6 damage (~14 average). If you up that to a +3 Impact scimitar it becomes 4d8 damage (~18 damage). For the same cost you can upgrade it to a +5 Scimitar instead it goes to 6d6 (~21 damage).

Now obviously you have to be smart about it, Impact was already bad at some things, but let's say you have a Longsword instead (one of the better options for Impact). A +3 Longsword does 4d8 damage (~18 damage). If you up that to a +3 Impact Longsword it becomes 8d6 damage (~28 damage). For the same cost you can upgrade it to a +5 Longsword instead it goes to 6d8 (~27 damage). They're almost identical in damage, but the +5 weapon is giving a +2 to hit.

Let's say you have a Bastard Sword instead (one of the BEST options for Impact). A +3 Bastard Sword does 4d10 damage (~22 damage). If you up that to a +3 Impact Bastard Sword it becomes 8d8 damage (~36 damage). For the same cost you can upgrade it to a +5 Bastard Sword instead it goes to 6d10 (~33 damage). Here we finally see ~3 extra damage from the Impact property, but you lose out on your to hit and your ability to overcome DR ... and this is one of the best options for Impact.

I should have qualified that it doesn't actually make Impact worse, you're just not gaining anything with Impact that you wouldn't get with another +2 enhancement. Once you have a +5 weapon the Impact property probably becomes one of the best (a +5 Impact Bastard Sword would be doing 12d8 damage, or ~54 damage per hit).

[Reversefigure4]

This seems good in that it tilts the balance of power toward weapon-attackers and away from spellcasters...

Yes, but not in a way that significantly matters. A Barbarian with a d12 Greataxe will kill things 5 times faster... but were double handed Barbarians in your games really having troubling dealing damage, or was it their inability to contribute when Melee Attacking is not the answer to the problem?