Is the Oversized Two-Weapon Fighting feat not worth it?

Question

The description of the Oversized Two-Weapon Fighting feat says (Complete Adventurer, p. 111):

You are adapted at wielding larger than normal weapons in your off hand.

Prerequisite: Str 13, Two-Weapon Fighting

Benefit: When wielding a one-handed weapon in your off hand, you take penalties for fighting with two weapons as if you were wielding a light weapon in your off hand (see page 160 of the Player's Handbook).

Special: A fighter may select Oversized Two-Weapon Fighting as one of his fighter bonus feats.

I have seen some discussions (like this one) and it seems most people are taking this as "just adding 1 point of dmg in average on off hand, not worth it". But when I took a deeper look at it, it seems wielding a one-hand weapon on off hand can bring some other benefits including:

• Removing the -4 panelty vs. Sunder
• Removing the -4 panelty vs. Disarm
• Can apply power attack (-5/+5 on both hands is essentially the same to -5/+10 on one hand, so you are just trading AB -2 with the extra weapon damage on your off hand. Not a bad trade if you are doing TWF already.)
• Having more hp vs. Sunder (low-level only, people are relying on enhancement bonuses at higher level)
• Open up additional off hand weapon options (especially when you are getting items generated by DM rather than creating by yourself)

I wonder why those benefits are overlooked especially when some monsters do have Improved Sunder or Improved Disarm in their feat lists (Water and Earth Elementals, giants, etc.; some even have those written in their default tactics, e.g. Titan), and some monsters actually have Sunder as an effective weakness (e.g. Kraken, Hydra, etc.). I feel that not taking this feat would likely let those TWF meleers say goodbye to their off hand weapons at the first round. (And I am feeling light weapons are really not very safe to play for frontline PCs.)

(It can potentially gain more dmg stack with Monkey Grip (Complete Warrior) but let's not consider it since it requires one more additional source.)

Answer 1

In a meta sense, Oversized Two-Weapon Fighting suffers from three primary problems:

1. Its innate benefit (higher base damage) is too small.

2. Enabling of Power Attack on Two-Weapon Fighting is irrelevant as most Power Attackers don’t use two-weapon fighting and most dual-wielders don’t use Power Attack.

3. For the few who do, unarmed strikes are much better than Oversized Two-Weapon Fighting, at the same or lower cost. Disarm and sunder aren’t really relevant the overwhelming majority of the time, but if you are worried about them, unarmed strikes are also immune to both.

That said, if you are going for Power Attack and Two-Weapon Fighting—probably as a ranger due to the requirement issues—and you really prefer two weapons over a bigger weapon and unarmed strikes, then Improved Oversized Fighting is probably good enough. Unarmed strikes are better. But Improved Oversized Fighting is not, in that case, terrible. It’s just that this is a very unusual case (again, perhaps excepting rangers).

To address your specific points in more detail,

• The damage benefit is small, usually +1 average on half your attacks. This increases as you get larger (e.g. short sword vs. longsword is +2½ at Large, +3½ at Huge and Gargantuan, +7 at Colossal), but 1. the largest numbers still aren’t all that large, 2. they still apply to half your attacks, and 3. getting larger than Large takes some effort and getting larger than Huge is quite a bit harder—outside of shapechanging anyway.

• Disarm and sunder are almost-never used; they are ineffective strategies for the most part, and few published monsters are built to attempt them (yes, a couple have at least one relevant feat, but it’s still not likely to ever be their optimal choice). In other words,

  I feel that not taking this feat would likely let those TWF meleers say goodbye to their off hand weapons at the first round. (And I am feeling light weapons are really not very safe to play for frontline PCs.)

  Your feelings on this matter are entirely off-base; this is a non-issue for dual-wielders in almost every case.

  Disarm is particularly poor since locked gauntlets grant an enormous +10 bonus; since those exist, why would anyone bother to try? On the other hand, sunder is widely considered “bad manners,” and even if you go for it, magic items get both hardness and hp in large quantities, making it really hard to actually achieve. At low levels, you don’t have feats enough to make Oversized Two-Weapon Fighting much of a consideration, anyway; you have (or, at least, should have) way too many other priorities first. If you were really worried about it, buying a back-up nonmagical short sword is really cheap even at 1st level.

• Power Attack is potentially a reason to consider Oversized Two-Weapon Fighting, except that unarmed strikes are massively superior:

  1. Despite being light weapons, you can use Power Attack with them.
  2. Improved Unarmed Strike is much more common as a bonus feat
  3. You can easily wield a two-hander for your “main” attack, gaining 2:1 benefits with those attacks, effectively making you “3:1” by your logic.
  4. If it actually comes up, unarmed strikes are entirely immune to disarm or sunder.

  The requirements on Power Attack and Two-Weapon Fighting are also problematic, making the combination less likely. A ranger might consider it thanks to their ability to ignore the Strength requirement on Power Attack or the Dexterity requirement on Two-Weapon Fighting, and Favored Power Attack exists to incentivize the combination even more—but they’re still way better off with a two-hander and unarmed strikes.

• Odd as it may sound, using randomized, found weapons is exceedingly unusual in D&D 3.5e, and rarely works well. Most weapon-wielding characters are built around a specific weapon—their feats may require it, and even if they don’t per se, their build relies on the particular properties that those weapons provide and other weapons don’t. Sure, in a pinch, a warrior will use whatever’s handy, but when the opportunity to sell your loot and get something tailored to your needs (whether that’s a magic mart or a crafter) comes up, every warrior is going to take it. In a campaign where those services are truly absent, a party becomes highly incentivized to have someone in the party able to perform them.