[House Rule] Fixing Two-Weapon Fighting Style

[HugeC]

The proposed house rule adds the following text to the end of the Two-Weapon Fighting Style description: "Alternatively, when two-weapon fighting you can use a bonus action to make one attack with your off-hand weapon for each attack you took with your Attack action, but you may not add your ability modifier to the damage on these attacks."

This would allow the two-weapon fighting style to scale as you get more attacks. As it stands, the duelist style does more damage than TWF at high levels, and it lets you use a shield. I wanted to make sure great weapon fighting still did the most damage with feat support, since the Dual Wielder feat offers +1 AC. This means that without feat support TWF falls a bit behind great weapon fighting, but with the house rule it is better than it would otherwise be.

Here is the spreadsheet I used to evaluate TWF performance vs. great weapon and duelist fighting styles, both with and without feat support and some multiclass scenarios: https://docs.google.com/spreadsheets/d/1Xw5V3FVGuk1pxjGsNdayElYyyEvz9fRDApF4ciRdsB8

The top part has calculations for one attack, and then below I've got damage per round for all attacks in various setups.

The corner case of the Fighter 12 / Warlock 8 using TWF and Hex looks better than a straight fighter in the spreadsheet, but in reality he's going to be spending bonus actions getting Hex up and switching targets, which will make him fall behind. I assume here that Lifedrinker is not allowed unless you are a Warlock 12 (to do otherwise would make Fighter 12 / Warlock 8 blow Fighter 20 out of the water, and that goes against the stated design intent).

So Playground, what do you think? Anything I've messed up in my analysis? Would you use this house rule, or do you have something else that tries to rebalance the fighting styles?

[Demonic Spoon]

To be clear, you balanced this exclusively for use with fighters?

Because TWF is used elsewhere and I could see this being problematic for other classes, like Ranger.

[edge2054]

I'm withholding judgement until I see magic items.

[HugeC]

I didn't even think about ranger! How would they interact with this rule?

[edge2054]

We've been talking about TWF rangers in this thread. Starts at post 50.

http://www.giantitp.com/forums/showthread.php?373325-Dual-wield/page2

[Easy_Lee]

Trouble is that fighters can take two weapon fighting style so that they do get attribute to damage with offhand attacks. So can rangers and barbarians. And GWF power attack is only really usable vs low AC (and, likely, weak) targets anyway. Consider four attacks with a great weapon vs duelist vs dual wielding, assuming rapiers:

GW: (2d6 + 5) * 4 = 48
DW: (1d8 + 5) * 5 = 47.5, but he used his bonus
Duelist: (1d8 + 2 + 5) * 4 = 46

The dual weilder above has basically the same damage as the great weapon fighter by optimizing for dual wield. And he gets to use Dex instead of str, meaning better reflex saves and initiative. The duelist is 2 points behind, but he gets a shield, and also gets to keep his bonus. However, GWF gets to reroll 1's and 2's, gets power attack as an option (a good option when you have advantage), and the GWF will pull ahead if he gets a crit and thus gets his bonus attack. It resolves in favor of the GW fighter overall for pure damage.

Here's what happens with your house rule:
DW: (1d8 + 5) * 8 = 76

Looks like he wins, especially since he can move between every one of those attacks. And what if that guy managed to pick up CS from ranger and applied it last round, then uses an action surge?
DW+AS+CS: (1d8 + 1d6 + 5) * 16 = 208.

He just outdamaged the hardest-hitting 9th level spell in one round, and can do it again two more times per short rest. Plus he has no MAD, great initiative, and can use his reaction for more AC with defensive duelist.

All of this assumes no magic items, which will help the dual wielder most out of everyone.

I guess you see the problem by now.

Edit: math was wrong on 208, should have been *12 for 156 since action surge doesn't grant an extra bonus (thought it did). As stated later in the thread, though, magic weapons (and poison) can shift the math a bit anyway, making OP's option the clear best anyway.

[Demonic Spoon]

Even the people most pessimistic about TWFing (Easy_Lee, for example) don't think that TWF is not viable. At worst, TWF is a slightly suboptimal choice depending on class and context (Which not everyone agrees with, even).

I don't think any potential issues are large enough to warrant a houserule.

[Aramis Rhett]

Agreeing with Demonic Spoon on this. It's a flavor choice. Yes there is a a slight lean in favor for Great Weapon Masters, but it's not huge enough to warrant a house rule to compensate something else.

[HugeC]

Easy_Lee: Take a look at my spreadsheet. The house rule I proposed does not add ability modifier to damage for the extra off-hand attacks.

Also, you wouldn't double the extra attacks if you used Action Surge, they would replace your single bonus-action attack that you get from two-weapon fighting now. So a Fighter 20 using action surge would get 8 main hand attacks and 4 off-hand attacks without ability mod to damage under the house rule.

Also also, you can't just multiply the damage times number of attacks to model it, because damage dice and modifiers are affected differently by crits (dice are doubled, modifiers are not). The spreadsheet takes crits into account.

Re: Rangers, it sounds like Hunter's Mark works like Hex? +1d6 damage to anything you hit? Or is it only once per round? I can try to work those into the spreadsheet tonight when I have my book handy to see what happens.

Edit: Sounds like I should add barbarians to my analysis as well.

[edge2054]

And to reiterate, magic items may shift the balance (a lot).

[edge2054]

Re: Rangers, it sounds like Hunter's Mark works like Hex? +1d6 damage to anything you hit? Or is it only once per round? I can try to work those into the spreadsheet tonight when I have my book handy to see what happens.

It's like Hex. CS is once per turn (but can trigger when it's not your turn, on an AoO for example).

[Demonic Spoon]

Easy_Lee: Take a look at my spreadsheet. The house rule I proposed does not add ability modifier to damage for the extra off-hand attacks.


That's great, but presumably a TWF fighter is taking TWF fighting style, which does let you add damage modifier to off-hand attacks.

[HugeC]

That's great, but presumably a TWF fighter is taking TWF fighting style, which does let you add damage modifier to off-hand attacks.
Read the OP. The whole point of the house rule is to let you choose 1 extra attack adding the ability modifier (you would do this at level 1), or 2+ extra attacks not adding it (this would give you a bit more damage at fighter 11, not sure about other classes yet).

[Demonic Spoon]

Where in the OP do you suggest changes to two-weapon fighting style? As far as I can tell you only proposed changes to the general TWF rules.

[HugeC]

The proposed house rule adds the following text to the end of the Two-Weapon Fighting Style description: "Alternatively, when two-weapon fighting you can use a bonus action to make one attack with your off-hand weapon for each attack you took with your Attack action, but you may not add your ability modifier to the damage on these attacks."

Bolded for emphasis. Also note the title of the thread.

[rlc]

And what if that guy managed to pick up CS from ranger and applied it last round, then uses an action surge?
DW+AS+CS: (1d8 + 1d6 + 5) * 16 = 208.

He just outdamaged the hardest-hitting 9th level spell in one round, and can do it again two more times per short rest. Plus he has no MAD, great initiative, and can use his reaction for more AC with defensive duelist.


Honestly, I think that martial characters on the whole should be doing more damage than the magical ones. Note that that's not an argument for one fighting style to be so clearly better than the others (so I don't think this house rule is a good idea, either), but for magic to be less about damage and more about effects.

[Galen]

GW: (2d6 + 5) * 4 = 48
DW: (1d8 + 5) * 5 = 47.5, but he used his bonus
Duelist: (1d8 + 2 + 5) * 4 = 46
By the level in which you have four attacks, you are extremely likely to have a magic weapon (in fact, I'd be shocked if you don't), so let's correct this to:

GW: (2d6 + 5 + 1) * 4 = 52
DW: (1d8 + 5 + 1) * 5 = 52.5, but he used his bonus
Duelist: (1d8 + 2 + 5 + 1) * 4 = 50, but he gets the shield AC

And if it's a +2 weapon:

GW: (2d6 + 5 + 2) * 4 = 56
DW: (1d8 + 5 + 2) * 5 = 57.5, but he used his bonus
Duelist: (1d8 + 2 + 5 + 2) * 4 = 54, but he gets the shield AC

And so on.

So for pure damage output, DW wins slightly, but eats up your bonus action.
Duelist trails slightly, but provides best AC and keeps the bonus action available.
GW is middle damage, no AC boost, but keeps the bonus action available.

All in all, I'd say the three are very close, and very well balanced.

[Aramis Rhett]

Honestly, I think that martial characters on the whole should be doing more damage than the magical ones. Note that that's not an argument for one fighting style to be so clearly better than the others (so I don't think this house rule is a good idea, either), but for magic to be less about damage and more about effects.

So true. Magic damage is WAY overpowered. A warlock boosting Eldritch Blast has one of the highest damage outputs in the game. And from a potentially ridiculous range (1,200 feet at most). And it's a cantrip, meaning they can sit back and sling those beams around like crazy.

[HugeC]

Honestly, I think that martial characters on the whole should be doing more damage than the magical ones. Note that that's not an argument for one fighting style to be so clearly better than the others (so I don't think this house rule is a good idea, either), but for magic to be less about damage and more about effects.
The math you quoted was completely wrong, just so you know.

[rlc]

The math you quoted was completely wrong, just so you know.

at least for the point that i was making, the math was less important than anything else that i quoted.

[HugeC]

I get the feeling nobody is bothering to open up the spreadsheet. Also, I found an error in my DPR formula, so let me copy some pertinent data into the thread. Initially I'm just comparing DPR values for the three fighting styles without support feats.

Ftr 20 two scimitars w/TWF, no feats: 32.375
Ftr 20 duelist sword & board, no feats: 34.9
Ftr 20 greatsword w/GWF, no feats: 42.33333322

^^^ This is what I'm trying to correct with the house rule.

Ftr 20 house rule TWF, scimitars: 37.8

^^^ This shows that it works, for level 20 champion fighters at least. The great weapon fighting style is still doing the most damage without any feat support.

Let's take a look at some magic weapon scenarios.

Ftr 20 +3 greatsword w/GWF & GWM: 67.76697193
Ftr 20 +3 longsword w/duelist: 52
Ftr 20 +3 longsword mainhand / nonmagic offhand w/TWF & DW: 52.525
Ftr 20 +3 longsword mainhand / nonmagic offhand w/TWF & DW house rule: 60.5

^^^ These assume a +3 main hand weapon. The house rule takes TWF from doing the same damage as duelist to being in the middle of duelist and GWF. Almost like I planned it!

Ftr 20 +2 longswords w/TWF&DW: 49.375
Ftr 20 +2 longswords w/TWF&DW house rule: 63

^^^ Now that was a bit unexpected. You actually do worse under the existing rules if you have a +2 weapon in each hand as opposed to a +3 weapon in your main hand. Under my house rule the damage goes up, but still not as high as GWF.

I think if you had a pair of +3 weapons, TWF probably ecplises GWF under my house rule, so if you're a DM considering, it would depend on whether you plan to give your TWF guys a pair of +3's or not.

Edit: Yeah, TWF with two +3 longswords eclipses GWF under the proposed house rule.
Ftr 20 +3 longswords w/TWF&DW: 56.5
Ftr 20 +3 longswords w/TWF&DW house rule: 73.4

[Easy_Lee]

Regarding your post concerning magic weapons, you also aren't considering poisoned weapons, or weapons that have effects like dealing fire damage or provoking a save. And bonus attacks are still extremely strong with collossus slayer.

Magical effects were a staple of previous editions. On hit confusion, on hit 1d4 fire damage, on hit push, etc are all pretty tame effects compared to some of the more dubious stuff out there. Even without the attribute, lots of separate hits can be devastating in the hands of a creative player. You know some cheeky fellow will want to dual wield lances while mounted.

Right now, dual wielding gives you inferior damage but better defense and one less stat to worry about. It also lets you win one v one fights with enemy martials most of the time because of defensive duelist and half shield bonus from dual wielder. Optimal dps or not, those bonuses are still something to consider.

If you really want to make DW an stronger option, try just adding one extra offhand attack for character level 13+. That gives you a total of 6 attacks at max, which is nice. Consider combining the DW and defensive duelist feats, since they aren't so strong by themselves but together would be quite potent. GWF will still pull ahead with haste or long strings of crits, but why shouldn't it? A GW Fighter put all of his resources into damage. He doesn't have the defensive capabilities of a defensive duelist, nor the initiative and reflex save bonuses.

I'm worried that your house rule will make the two hander guy feel useless.

[Yagyujubei]

Regarding your post concerning magic weapons, you also aren't considering poisoned weapons, or weapons that have effects like dealing fire damage or provoking a save. And bonus attacks are still extremely strong with collossus slayer.

Magical effects were a staple of previous editions. On hit confusion, on hit 1d4 fire damage, on hit push, etc are all pretty tame effects compared to some of the more dubious stuff out there. Even without the attribute, lots of separate hits can be devastating in the hands of a creative player. You know some cheeky fellow will want to dual wield lances while mounted.

Right now, dual wielding gives you inferior damage but better defense and one less stat to worry about. It also lets you win one v one fights with enemy martials most of the time because of defensive duelist and half shield bonus from dual wielder. Optimal dps or not, those bonuses are still something to consider.

If you really want to make DW an stronger option, try just adding one extra offhand attack for character level 13+. That gives you a total of 6 attacks at max, which is nice. Consider combining the DW and defensive duelist feats, since they aren't so strong by themselves but together would be quite potent. GWF will still pull ahead with haste or long strings of crits, but why shouldn't it? A GW Fighter put all of his resources into damage. He doesn't have the defensive capabilities of a defensive duelist, nor the initiative and reflex save bonuses.

I'm worried that your house rule will make the two hander guy feel useless.

collossus slayer can only be applied once per round. otherwise it would be game breaking

[Easy_Lee]

collossus slayer can only be applied once per round. otherwise it would be game breaking

Ah, well nevermind on that then. Magic weapons still apply.

[Hytheter]

What if TWF gave advantage instead? You get the extra rolls and increased chance of hitting, without totally unbalancing things if you get extra +1s. Flavour wise, it'd be like instead of trying to hit your opponent with every strike with both weapons, you're instead using the off-hand to feint and overwhelm your opponent, making it easier to land attacks with the main weapon.

Have it no longer waste the bonus action and you get something that's less powerful but far more accurate than the other styles.

You'd have to change the feat of course; maybe just make it so you add double STR/DEX on a successful hit, or get to add your off-hand weapon's damage dice.

[TheOOB]

The two-weapon fighting style is fine as is. For fighters is a decent but not great combat option, that actually becomes really solid with the accompanying feat, and for the ranger it's already really good.

Some quick number(assuming 20 Strength)

Duelist

1 Attack: 11.5 dmg
2 Attacks: 23 dmg
3 Attacks: 34.5 dmg
4 Attacks: 46 dmg

All levels +2 AC for shield

TWF

1 Attack: 17 dmg
2 Attacks: 25.5 dmg
3 Attacks: 34 dmg
4 Attacks: 42.5 dmg

TWF with Feat

1 Attack: 19 dmg
2 Attacks: 28.5 dmg
3 Attacks: 38 dmg
4 Attacks: 47.5 dmg

+1 AC at all Levels

GWF

1 Attack: 13.3 dmg
2 Attacks: 26.6 dmg
3 Attacks: 40 dmg
4 Attacks: 53.3 dmg

With the feat, TWF is a very strong option, both early and late, competitve with the other fighting styles at the cost of a feat. Without the Feat TWF is still the best style for 1 attack, nearly the best for 2, and decent at 3, only really showing problems at 4 attacks, which is only at fighter level 20.

So yes, if you don't have a feat to spare to get near near GWF damage at high level(and better at low) with an AC boost, TWF is not the best if you plan on going straight fighter. But if you plan on multiclassing(or you're a ranger) it's AMAZING with or without the feat. Any buffs to the style would likely make TWF too powerful for non straight fighters.

[Strill]

Even the people most pessimistic about TWFing (Easy_Lee, for example) don't think that TWF is not viable. At worst, TWF is a slightly suboptimal choice depending on class and context (Which not everyone agrees with, even).

I don't think any potential issues are large enough to warrant a houserule.

I think what Two-Weapon fighting really needs is a good feat to give it some "umph". Greatswords have Great Weapon Fighting. Polearms have Polearm Master. Those two feats pretty much define their respective weapons. Dual weapons have Defensive Duelist, which is great, but the Two Weapon Master feat is worse than a plain old +2 DEX. If you gave two-weapon fighters a really good feat, I think they'd become a more favorable option.


With the feat, TWF is a very strong option, both early and late, competitve with the other fighting styles at the cost of a feat. Without the Feat TWF is still the best style for 1 attack, nearly the best for 2, and decent at 3, only really showing problems at 4 attacks, which is only at fighter level 20.

So yes, if you don't have a feat to spare to get near near GWF damage at high level(and better at low) with an AC boost, TWF is not the best if you plan on going straight fighter. But if you plan on multiclassing(or you're a ranger) it's AMAZING with or without the feat. Any buffs to the style would likely make TWF too powerful for non straight fighters.

You're ignoring the fact that there are ways for Great-Weapon Fighters to get bonus actions. Polearm Mastery, for example, is pretty much flat-out better than Dual Weapons. Great Weapon Fighter also gives you bonus actions fairly reliably.

You also don't account for additional actions from opportunity attacks, and from Haste, which push 2-handers even further ahead.

[TheDeadlyShoe]

and for the ranger it's already really good.

I like the Ranger, but you have got a lot of things to do with your bonus action as it is. TWF could just end up taking a back seat a lot of the time. If you're a Beastmaster, forget it!

[HugeC]

So I added some ranger stuff to my spreadsheet, and my conclusion is that Rangers Be Crazy. They are awesome at level 5 (assuming 6 spell slots spent on Hunter's Mark is enough to have it up all the time), and pretty much never get any better. Here are some initial calcs:

Rgr 5 duelist rapier w/HM & CS: 23.17375
Rgr 5 TWF scimitars w/HM & CS: 27.0320625
Rgr 5 TWF scimitars w/HM & CS house rule: 29.45747188

^^^ These are trying to account for Colossus Slayer with some math that figures the probability of at least one attack hitting to add +4.5 damage, and if the first attack is a crit to add another 4.5 damage. This is because you only have 2-4 attacks so you're probably going to take CS as soon as you can, rather than fishing for a crit to apply it to.

On rounds when you apply Hunter's Mark, the duelist's damage stays the same, while the TWF ranger misses out on off-hand damage. You probably need to average the DPR for a round with and a round without off hand attack(s) to get a more accurate number.

Rgr 5 TWF scimitar w/HM & CS, no off hand attack: 19.32
Rgr 5 TWF scimitars w/HM & CS: 27.0320625
Average: 23.176, pretty much the same as the duelist

Using my house rule the average becomes:

Rgr 5 TWF scimitar w/HM & CS, no off hand attack: 19.32
Rgr 5 TWF scimitars w/HM & CS house rule: 29.45747188
Average: 24.3887, TWF now has a very slight advantage over duelist

The great weapon fighter doesn't catch up with this kind of damage until level 11, but using my house rule doesn't affect that disparity one way or the other, it just makes TWF a SLIGHTLY more damaging choice than duelist at the cost of 2 AC.

At level 20, the difference is slightly more pronounced, though the numbers aren't much higher

Rgr 20 duelist rapier w/HM & CS: 26.12
Rgr 20 TWF rapiers w/DW, HM & CS: 33.1035
Rgr 20 TWF rapiers w/DW, HM & CS house rule: 35.68855
Rgr 20 TWF rapier w/DW, HM & CS, no off hand attack: 23.32
Average TWF damage: 28.21175
Average TWF damage with house rule: 29.504275

Keep in mind that the TWF ranger has spent a feat on Dual Wielder here, whereas the duelist has not. At least the TWF ranger does more damage than a duelist without my house rule, but again, it's not a huge difference.

The point others have made about magic items affecting the balance is valid, but far less so with rangers as they only have 2 attacks. I'll need to look at Fighter 12 / Ranger 5 later to see how that shakes out.

[TheOOB]

You're ignoring the fact that there are ways for Great-Weapon Fighters to get bonus actions. Polearm Mastery, for example, is pretty much flat-out better than Dual Weapons. Great Weapon Fighter also gives you bonus actions fairly reliably.

You also don't account for additional actions from opportunity attacks, and from Haste, which push 2-handers even further ahead.

I wasn't ignoring it so much as it wasn't relevant to what I was trying to stat. Without the feat TWF is great for non-fighters and for low level fighters, but meh for high level fighters. With the feat, TWF is a solid and defensible choice for any character, providing significantly more damage than the dualist style while still providing some of the AC.

GWF is still the highest damage option for a high level fighter, and yes, polearm mastery is amazing, but my point is that TWF is good enough that buffing it in any way runs the risk of making several character archtypes too powerful just to make one specific high level character archtype less underwhelming.

[HugeC]

With the feat, TWF is a solid and defensible choice for any character, providing significantly more damage than the dualist style while still providing some of the AC.

This is factually incorrect even at level 1. TWF with Dual Wielder does less damage than duelist + polearm master using a quarterstaff one-handed. Without feats it's the same for fighters at levels 5+. The math in your previous post is way off. Not saying mine is perfect, and using a spreadsheet is annoying, but you can't just multiply average damage times number of attacks to judge these things.

[Easy_Lee]

I still say that the simplest thing to do is to give dual wield one extra bonus attack at 13, yielding a final maximum of 6. It's not too crazy, it beats duelist, and it doesn't make TWF eclipse GWF. As I've said, GWF should do more damage because its defenses, initiative, and reflex are lower.

Plus, if your weapons have bonus damage like radiance, or force a save such as a poisoned weapon, TWF can do some pretty cool stuff already. It's all dependant on gear.

And I still think combining dual wielder and DD to one feat would be a good idea. It gives you one extra weapon draw, +1 ac, d6 > d8 = +1 damage per hit, and the DD reaction. Sounds like a reasonable feat to me.

[Rilak]

This is factually incorrect even at level 1. TWF with Dual Wielder does less damage than duelist + polearm master using a quarterstaff one-handed. Without feats it's the same for fighters at levels 5+. The math in your previous post is way off. Not saying mine is perfect, and using a spreadsheet is annoying, but you can't just multiply average damage times number of attacks to judge these things.

There are more classes than Fighters...

TWF is incredibly strong for Rogues even without feats. Adding this change would make Rogues love you for their 4 easy hits per turn.
So would warlocks with their hex.
Or maybe a Warlock/Paladin with a level of Fighter for some yummy extra d6/d8s.

[Theodoxus]

I just skimmed the replies, so if I missed this point, I apologize. My singular issue with this proposal is it dances really closely to breaking the Bonus action economy.

I only bring this up because I was playing with a monk last night, and the DM didn't catch that he was TWF (bonus action), Martial Attacking (bonus action) and spending a Ki point to flurry (bonus action) - the monk kept missing, so I wasn't overly worried - and only used 1 attack when flurrying - so he was overall only making one attack more than he should be... but the point stands.

One could legitimately argue that you're making an attack with your primary, bonus attacking with your off-hand, using extra attack to attack with your primary, and making a second bonus attack with your off-hand.

Outside of that one sticking point, I think it's a decent houserule...

[HugeC]

In an earlier version of the spreadsheet, I had experimented with using Great Weapon Master's -5 to hit / +10 damage feature and found that it decreased DPR. Now when I use it, at least on a level 20 fighter, it increases DPR. It turns out that a great weapon fighter using a +3 greatsword and -5/+10 out-damages the TWF fighter with a pair of +3 longswords.

Ftr 20 +3 greatsword w/GWF & GWM: 67.76697193
Ftr 20 +3 greatsword w/GWF & GWM, power attack: 76.34979232
Ftr 20 +3 longsword w/duelist: 52
Ftr 20 +3 longswords w/TWF & DW: 56.5
Ftr 20 +3 longswords w/TWF & DW house rule: 73.4

I don't know how this affects the comparison at other levels yet, more later when I have time.

[HugeC]

OK, ran some numbers for a Fighter 12 / Ranger 5, who gets Hunter's Mark and Colossus Slayer to help his damage.

Ftr 12 / Rgr 5 GWF greatsword w/GWM, HM, & CS: 48.987
Ftr 12 / Rgr 5 GWF greatsword w/GWM, HM, & CS, no bonus attack: 45.3285

Ftr 12 / Rgr 5 TWF w/DW, HM & CS: 44.51355
Ftr 12 / Rgr 5 TWF w/DW, HM & CS house rule: 53.8467195
Ftr 12 / Rgr 5 TWF w/DW, HM & CS, no bonus attack: 34.5285

2-round average for GWF: 47.15775
2-round average for TWF: 39.521025
2-round average for TWF with house rule: 44.18760975
Ftr 12 / Rgr 5 duelist w/HM & CS: 38.7285

For reference, here are my current Fighter 20 numbers for the same styles:
Ftr 20 greatsword w/GWF & GWM, power attack: 52.61642567
Ftr 20 TWF longswords w/DW: 36.625
Ftr 20 TWF longswords w/DW, house rule: 44.6
Ftr 20 duelist sword & board, no feats: 34.9

So, for a fighter 12 / ranger 5, you don't need a house rule for TWF to barely eke out more damage than duelist. Since fighter is in the mix, GWF is an option, and that guy will have to put up / switch Hunter's Mark as well, so I did 2-round averages for all of them. Once again it works out about right with the house rule, though if I had my druthers it'd be a half a point to a point lower.

For the GWF I figured Great Weapon Fighting Style lets you re-roll 1's and 2's on the Hunter's Mark die, and come to think of it, I didn't do that on Colossus Slayer damage, but I think I should, so the GWF damage should probably be a tad higher. The rule says, "When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon..." Seems like it should apply. And now I know why you can't sneak attack with a greatsword; that would be too awesome a combo.

Anyway, I'mma stop posting now, as I've convinced myself (if nobody else) that the house rule works as intended, caveats for magic items / poison notwithstanding. If it helps you, great! If not, thanks for reading.