Two-Weapon Fighting

I like the new take on it, but I think it is too strong.
Here is how I see the three main fighting styles:
1) Weapon and Shield.  Lowest damage, but high defense.
2) Great Weapon.  Highest damage.
3) Two Weapons.  High flexibility.

With two weapons you can attack two targets with a single action.  Alternatively, you get two chances to hit a single target, increasing your chance to deal at least some damage.  As a result, I think a two-handed weapon should deal more damage.

Currently, this isn't the case.  The Heavy weapons deal 1d12 damage.  You can wield two light weapons, which can do 1d6 damage each.  So Heavy gets 1d12 + Str mod compared to 2d6 + Str mod for two weapons (or you can split it up and attack two targets).  Now, it is true that your chance of hitting twice (and thus dealing more damage) is less than the chance of hitting once with the Heavy weapon, but I still think it is too much.

Especially when you add in the extras you can get through feats.  There is no way to enhance a Heavy weapon through feats, but there are 3 feats for Two-Weapon Fighting.  One gives +1 AC (more on that later), one lets you use a bigger weapon in your main hand (increasing your potential damage even more), and the last lets you add your stat mod to the second attack if you hit the same creature with both attacks.  The last one is the most troubling, as it results in the exact type of damage stacking that has ruined two-weapon fighting in every single past edition.

As for the AC, I think it should be a trade-off.  Allow your off-hand weapon to count as a shield until the start of your next turn as long as you don't make any attacks with it.  This gives good versatility, as every round you can pick between offense and defense.  Along these lines, the Spiked Shield seems far too good.  You are getting the effect of the feat (but better, because you get a +2 to AC) for free.  Given the fact that Shields already come with very good support, this options seems way too strong.  I would first of all make the Spiked Shield not a light weapon.  It is a heavy shield with big spikes...hardly seems the same as a short sword.  Second, I would use the same trade-off mechanic: if you attack with the shield you don't get the defense bonus for that round.

Here is how I would change two-weapon fighting:

You get two attacks (both light weapons) with no stat mod to damage.
Two-Weapon Defense feat as above.
Dual Wielding feat as printed.
Two-Weapon Strike feat lets you apply your stat modifier to damage if you attack separate targets with each weapon.

We also need clarification on how two-weapon fighting interacts with multiattack.
My blogs: Spell Flavor Reflavoring Uses of Spells
One thing to consider: you can only add Deadly Strike damage to one attack. So a level 20 fighter dual-wielding a longsword and shortsword who hits with both deals 5d8+Str+1d6+Str damage (36 average assuming 20 Str) with at least two feats, while a fighter with a greatsword deals 5d12+Str (32.5 average) without any feats.
You only add your ability modifier to damage to your first attack.


But in either case, I don't agree with how two weapon fighting is handled here.


I'd prefer both attacks benefit from deadly strike and the ability mod to damage, but I'd halve the ability mod on both attacks and deny the ability to weild anything but a light weapon with it.
One thing to consider: you can only add Deadly Strike damage to one attack. So a level 20 fighter dual-wielding a longsword and shortsword who hits with both deals 5d8+Str+1d6+Str damage (36 average assuming 20 Str) with at least two feats, while a fighter with a greatsword deals 5d12+Str (32.5 average) without any feats.

Ooo, good point, I was just thinking about level 1...I didn't consider the effect of Deadly Strike.

So I guess it is pretty good as is.  Two-Weapon fighting can deal more damage IF you hit with both attacks and use up two of your 4 feats, but it isn't very much extra damage at all.

In conclusion, I take it all back...two-weapon fighting as is might be just fine!

But I would still like clarification regarding two-weapon fighting and Multiattack.

Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.
Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.

Rats.  Time for math.

Level 20, Strength of 20, non-magic weapon.  Use monster AC of 16 (pretty good value for tougher foes I think).

Greatsword: +10 to hit, 5d12 + 5 damage, 1d12 + 65 on a critical hit.
Miss: 25%
Hit: 70%.  Average damage: 26.3
Crit: 5%.  Average damage: 3.6
Total Average Damage: 29.9 (call it 30).
Note: Your expertise dice help a lot for the attack roll, because you are putting everything into one big attack.  Careful attack brings your average damage up to between 31.7 and 37.4.  The exact value depends on the roll, but against AC 16 you end up hitting on a 2+ 50% of the time (you need to roll a 4+ on the d6).  In addition, Glancing Blow is a better option for the great weapon compared to two-weapons.

Two-Weapons (no feats): +10 to hit, 1d6+5 (1d6 + 11 on a crit) and 1d6 (1d6 + 6 on a crit).  Deadly Strike of 5d6 once/turn.  Assumed to add Deadly Strike dice at first opportunity.
Miss both: 6.25%
1 hit (main hand): 17.5%.  Average damage: 3.9
1 hit (off-hand): 17.5%.  Average damage: 3.1
2 hits: 49%.  Average damage: 12.7
1 crit (main), 1 miss (off): 1.25%.  Average damage: 0.5
1 crit (off), 1 miss (main): 1.25%.  Average damage: 0.4
1 crit (main), 1 hit (off): 3.5%.  Average damage: 1.5
1 hit (main), 1 crit (off): 3.5%.  Average damage: 1.1
2 crits: 0.25%.  Average damage: 0.1
Total Average Damage: 23.3
Notes: Again, Careful Attack can help here, but it wouldn't lead to as much of an increase to damage.

So without feats, it is actually just where I want it.  Two-weapons deals less damage on average, but gives you versatility (you can attack two things).

With the two feats, the numbers become:
Miss both: 6.25%
1 hit (main hand): 17.5%.  Average damage: 4.8
1 hit (off-hand): 17.5%.  Average damage: 3.9
2 hits: 49%.  Average damage: 17.6
1 crit (main), 1 miss (off): 1.25%.  Average damage: 0.6
1 crit (off), 1 miss (main): 1.25%.  Average damage: 0.4
1 crit (main), 1 hit (off): 3.5%.  Average damage: 2.0
1 hit (main), 1 crit (off): 3.5%.  Average damage: 1.5
2 crits: 0.25%.  Average damage: 0.2
Total Average Damage: 31

So even with two feats, the average damage is only 1 point higher!  I guess this version of two-weapon fighting is actually awesome.  It gets my official seal of approval!

Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.



It is important to remember that, in this iteration of the rules, this deadly strike will generally only be half as powerful as a two-handed weapon's deadly strike. While a dual weapon warrior has two chances to get a deadly strike in a turn, it will inflict xd6 damage instead of xd12.
Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.



It is important to remember that, in this iteration of the rules, this deadly strike will generally only be half as powerful as a two-handed weapon's deadly strike. While a dual weapon warrior has two chances to get a deadly strike in a turn, it will inflict xd6 damage instead of xd12.

Yup, which is why things come out pretty well-balanced.

Still leaves the issue of the Spiked Shield.  You get +2 to AC (meaning you don't need to pick up the Two-Weapon Defense feat) and still get to make those attacks.  I think that pushes it a bit too far beyond, as you get the defense of weapon/shield plus the damage of a heavy weapon (with feat investment).  Making the Spiked Shield no longer a light weapon would help (as it would require you to take the Dual Wielding feat and use a light weapon in your other hand in order to use the shield as part of two-weapon fighting).  I think this would actually be enough of a fix, as it requires a feat to bring you up to 1d6/1d6 damage (instead of 1d8/1d6). 

Personally, I don't see any reason for dual weapon fighting and two-handed fighting to have a different average damage output. They are already distinguished by the dual weapon's ability to spread damage and ensure a greater chance at inflicting some damage with the two-hander's ability to have a greater chance to inflict more damage in a single strike.
Personally, I don't see any reason for dual weapon fighting and two-handed fighting to have a different average damage output. They are already distinguished by the dual weapon's ability to spread damage and ensure a greater chance at inflicting some damage with the two-hander's ability to have a greater chance to inflict more damage in a single strike.

Don't forget that with two weapons you also have a far lower chance of dealing no damage.

I think it is pretty well balanced right now. 

Personally, I don't see any reason for dual weapon fighting and two-handed fighting to have a different average damage output. They are already distinguished by the dual weapon's ability to spread damage and ensure a greater chance at inflicting some damage with the two-hander's ability to have a greater chance to inflict more damage in a single strike.

Don't forget that with two weapons you also have a far lower chance of dealing no damage.

I think it is pretty well balanced right now. 




I did factor in the far lower chance of inflicting no damage when I said, "ensure a greater chance at inflicting some damage."


I don't think the disparity is too crazy right now, I just think the current solution is incredibly inelegant.
Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.



It is important to remember that, in this iteration of the rules, this deadly strike will generally only be half as powerful as a two-handed weapon's deadly strike. While a dual weapon warrior has two chances to get a deadly strike in a turn, it will inflict xd6 damage instead of xd12.

Yup, which is why things come out pretty well-balanced.

Still leaves the issue of the Spiked Shield.  You get +2 to AC (meaning you don't need to pick up the Two-Weapon Defense feat) and still get to make those attacks.  I think that pushes it a bit too far beyond, as you get the defense of weapon/shield plus the damage of a heavy weapon (with feat investment).  Making the Spiked Shield no longer a light weapon would help (as it would require you to take the Dual Wielding feat and use a light weapon in your other hand in order to use the shield as part of two-weapon fighting).  I think this would actually be enough of a fix, as it requires a feat to bring you up to 1d6/1d6 damage (instead of 1d8/1d6). 


How would you feel about alternatively leaving Spiked Shields light, but dropping damage to 1d4 Slashing?
Well, it's still pretty darn powerful since I think you can use Deadly Strike on the off-hand attack even if you miss with the main-hand attack.



It is important to remember that, in this iteration of the rules, this deadly strike will generally only be half as powerful as a two-handed weapon's deadly strike. While a dual weapon warrior has two chances to get a deadly strike in a turn, it will inflict xd6 damage instead of xd12.

Yup, which is why things come out pretty well-balanced.

Still leaves the issue of the Spiked Shield.  You get +2 to AC (meaning you don't need to pick up the Two-Weapon Defense feat) and still get to make those attacks.  I think that pushes it a bit too far beyond, as you get the defense of weapon/shield plus the damage of a heavy weapon (with feat investment).  Making the Spiked Shield no longer a light weapon would help (as it would require you to take the Dual Wielding feat and use a light weapon in your other hand in order to use the shield as part of two-weapon fighting).  I think this would actually be enough of a fix, as it requires a feat to bring you up to 1d6/1d6 damage (instead of 1d8/1d6). 


How would you feel about alternatively leaving Spiked Shields light, but dropping damage to 1d4 Slashing?



I think that all they really need to do is actually add some feat support for two-handed fighting.  Its the only reason that TWF can start to look better in terms of offensive output.  With the feats, sure you are dealing about the same damage with a better AC, but that is with half of your feats.  I think there just need to be some 2-handed feats.  

Although... the other thing to keep in mind is that there are a few feats like Shove Away, tripping attack, charge and disarming attack that specifically state that you make a single attack which is advantage to the 2-hander.  The other side of this is also to remember that any attack made with a reaction will also give the edge to the 2-hander, so any player expecting to heavily use the Riposte feat will benefit more by using a 2-hander.
Very interesting back and forth here...I came on to the forum with much doubt about the parity between TWF and 2HF and have found some of my fears assauged with the mathematical model presented by Arithezoo above (thanks!)...still feel like the d10 2HW (katana, specifically, but also the bastard sword and most polearms) get shafted (yep) compared to the two short swords combo (of which i predict there will be MANY)...maybe we (and by that i mean Arithezoo) could do a d10 model to compare as well...
I did factor in the far lower chance of inflicting no damage when I said, "ensure a greater chance at inflicting some damage."

Oops, sorry, I totally missed that!
How would you feel about alternatively leaving Spiked Shields light, but dropping damage to 1d4 Slashing?

I'd be cool with that.  Maybe also lower the defense bonus to +1 (but have it stack with Two-Weapon Defense).  But I'm really just spitballing here.
I think that all they really need to do is actually add some feat support for two-handed fighting.  Its the only reason that TWF can start to look better in terms of offensive output.  With the feats, sure you are dealing about the same damage with a better AC, but that is with half of your feats.  I think there just need to be some 2-handed feats.  

Although... the other thing to keep in mind is that there are a few feats like Shove Away, tripping attack, charge and disarming attack that specifically state that you make a single attack which is advantage to the 2-hander.  The other side of this is also to remember that any attack made with a reaction will also give the edge to the 2-hander, so any player expecting to heavily use the Riposte feat will benefit more by using a 2-hander.

I completely agree, with both parts.  Extra feat support for Heavy (or two-handed) weapons would be cool.  And at the same time they sort of already have them, the difference is that they aren't focused on dealing extra damage.  But maybe that is ok.  You already deal a lot of base damage, so when you specialize you gain utility/versatility.
Very interesting back and forth here...I came on to the forum with much doubt about the parity between TWF and 2HF and have found some of my fears assauged with the mathematical model presented by Arithezoo above (thanks!)...still feel like the d10 2HW (katana, specifically, but also the bastard sword and most polearms) get shafted (yep) compared to the two short swords combo (of which i predict there will be MANY)...maybe we (and by that i mean Arithezoo) could do a d10 model to compare as well...

Yes!  Math has assauged fears!  Another victory for mathematics.
But seriously, you are welcome.  I am a former math teacher, so it is nice to get the chance to solve a little problem.

Here are the numbers for 1d10 two-handers:
+10 to hit, 5d10 + 5 damage, 1d10 + 55 on a critical hit.
Miss: 25%
Hit: 70%.  Average damage: 22.8
Crit: 5%.  Average damage: 3.0
Total Average Damage: 25.8 (call it 26).

So only 4 points less average damage compared to the 1d12.  Not a game breaker at all.  And still a bit higher than two light weapons with no feat support.  Given that these weapons all bring something else to the table (bastard sword can be used in one or two hands, katana is a finesse weapon, glaive has reach, etc), I think it is pretty well balanced.


Other than flavor I'm still trying to figure out if there's a reason for a shield fighter not to use a rapier and a spiked shield... Same damage as a battleaxe or long sword but with the additional chance for d6...
Where does the additional chance for d6 with the rapier come from? I just don't see it. I must be missing it......
Where does the additional chance for d6 with the rapier come from? I just don't see it. I must be missing it......

I think he's referring to the d6 from the spiked shield?  Anyways, a rapier is finesse, but not light.  A fighter with a rapier and a spiked shield can't attack with both on the same turn unless he has the Dual Wielding feat.  And if he has that feat, there's no reason he can't use a long sword or battle ax or rapier...
Yes, the d6 was the spiked shield and yes, I'm not sure why I thought the rapier was a light weapon.
Heh, if it were up to me, the rapier and the scimitar should swap spots.  I mean, when it comes to swords, how do you get any lighter that a rapier?!
Heh, if it were up to me, the rapier and the scimitar should swap spots.  I mean, when it comes to swords, how do you get any lighter that a rapier?!


Actually, in real life the average rapier weighed about 3lbs.  Which by the way, is the average weight of a D&D long sword, or real lift Arming Sword that Knights used to carry.

So really, I wish it wasn't, because it's inaccurate and creates favourtism situations like this one.
Where are the new rules for two-weapon fighting?  I expected to find them in the How to Play document, but if it's in there I must have missed it.  So far I've only found the feats that modify how two-weapon fighting works, which assumes you already read the basic rules for it.

Edit: Nevermind.  Of course, as soon as I ask I find it on page 16 of How to Play.  I must have been expecting a bigger heading for it.
Basically, you can only use two weapons if both are light weapons. You get an extra attack each round but you don't add your modifier to the damage roll of the second attack. 'How to Play' page 16 under Melee Attacks.
I consider Riposte to be feat support for 2h weapons.


"When Friday comes, we'll all call rats fish." D&D Outsider
Heh, if it were up to me, the rapier and the scimitar should swap spots.  I mean, when it comes to swords, how do you get any lighter that a rapier?!

I thought the same thing, until I realized that people actually CAN dual-wield scimitars effectively, and (appart from the three musketeers) CAN'T effectively wield two rapiers effectively.  (Though I'm sure someone will argue the point)

Oh and multiattack favours the two-handers too, because attacking with two weapons is an action, and whirlwind attacking is an action.  So the dual-wielder doesn't get off-hand attacks while whirlwinding, and the two-hander gets just as many attacks.
I have heard a lot of complaints from other forums that people can no longer use paired longswords/battle axes. The new TWF works well, mathwise, however, it's too bad that some people may be able to play their character as they envision.

Maybe it could be a rule that you can dual-wield with any one-handed weapon, but if you attack twice in one turn, the damage die drops to d6. Realistically, two swings on a target at the same time wouldn't cause a deep of a wound as one stroke with all one's power behind it. Light weapons will keep the d6 damage, where as longswords and battleaxes will drop to d6. When a player takes two-weapon fighting feat, he/she can increase the main weapon damage one die step.
First: There are 1d10/1d4 double weapons, urgosh and halberd/glaive with feats


Second: Two-handers still do better for attacks of opportunity and other reaction-based attacks


In theory it's possible to use a lance in the main hand and a light weapon in the off-hand. The problem is such a combo has either a disadvantage on the lance's 1d12 at 5ft; or has to use whip (only 1d4 no mod) at 10ft
Its your "concept" thats wrong... not the rules.
If my concept is to wield 2 two handers like in diablo I cant do that either, that doesnt make the rules bad but my concept. So just because a 4m tall car robot has a concept with a longsword and battleaxe it doesnt nesceserrily make it a good concept for d&d...
 Your "good idea" about -2 was in former packets/games and have been discarded because they were bad math, so no need to playtest that again.
 "but its a dealbreaker if i dont have two longswords" get a longsword and a shortsword ruleswise and call one a longsword in your mind.
"nooo i dont want to roll different dice it ruins my game flow" *sigh* ok...get two shortsword swords and apply above mentioned mind trick.
"NoNoNo because then I do an average 1 less damage and doing MAX possible damage is also part of my roleplaying concept" Youre stretching it a bit here arent you?
 
 I agree that dual wielding is a bad pre req for the level 9 feat as not all want to use one handers so its a bit of a wasted feat for them. 
It's much better to allow a feat to dual wield with two long swords at level 1, but both at -2 / -2 like earlier editions.



I think I am confused a bit about the two weapon fighting - the way i understand it is this:

With dual weild feat and a rapier in main hand and scimitar in off hand, i am confused about these two things:   (1) both attacks are at -2 penalty (Is this correct?  I can't find it in the How to Play section?), (2) Off hand weapon does not add Dex mod to either Attack OR Damage?

Is this correct?

It's much better to allow a feat to dual wield with two long swords at level 1, but both at -2 / -2 like earlier editions.



I think I am confused a bit about the two weapon fighting - the way i understand it is this:

With dual weild feat and a rapier in main hand and scimitar in off hand, i am confused about these two things:   (1) both attacks are at -2 penalty (Is this correct?  I can't find it in the How to Play section?), (2) Off hand weapon does not add Dex mod to either Attack OR Damage?

Is this correct?




The attack penalty has been removed so in your example you would do the following:

Rapier


  • Roll 1d20 add your Str modifier and the weapon attack bonus from your class

  • If you hit, roll 1d8 and add your Str mod


Scimitar


  • Roll 1d20 add your Str modifier and the weapon attack bonus from your class

  • If you hit, roll 1d6



Since both weapons are Finesse weapons you can replace your Strength modifier with your Dexterity modifier.
 
I think a better way to handle 2-handed weapons doing more damage is to just allow them to apply 2x STR mod and then balance by adjusting the actual weapon damage die (such as d8 instead of d12).  Then you can allow dual wielders (with light weapons) to apply their stat mod twice.  It may require a bit of balancing against those who choose to wield just one 1-handed weapon, but if you're using a shield in the other hand then it was a choice you made of defense (+2 AC) over offense (extra attack/extra damage).  Drop feats like "Two Weapon Defense" and just let the player choose from round to round if they are going to attack with their off hand (extra attack) or use it for defense (+1 AC).
Thanks Swamp_Slug!  Anyone know where i can find in the new Playtest docs that the attack penalty has been removed?  I cannot find any mention of the penalty but i gues it was in previous playtests?
I read p. 16 of How to Play and it does not mention anything about the -2 penalty to both weapons, or not applying the Str bonus to the off hand attack.  The group  I just started playing with uses this so that is why i am probably confused since i did not play the previous playtest packets.

So because they are not mentioned in this packet does tht mean that these penalties are gone?
Yes forget anything from other packs. Read his from scratch
I've dug into some math behind the 1x2h vs 2x1h and in the end I wanted to see exactly when it was better to use one or the other.

So I made a big spreadsheet and got a lot of graphs. Here's the graph for the most simple case : No advantage, 11 or more on the d20, +3 Str mod, 2 x d6 wpns vs 1 x d12.

IMAGE(http://i.imgur.com/iTAjrRK.png)

If you want to play around and see the more advanced examples (Advantage, Weapon Mastery, Two-Weapon Strike) I've uploaded the files.
One is in .odf format (I use LibreOffice, free + Open Source), the other is in .xls format (Office 2000/2003) if you've got that :
 

docs.google.com/file/d/0B1h93rzjdElVenhi...


Just to make things even more complicated....I wish there were an incentive (feats?) for single-wielding a 1H weapon.
"Therefore, you are the crapper, I'm merely the vessel through which you crap." -- akaddk

Just to make things even more complicated....I wish there were an incentive (feats?) for single-wielding a 1H weapon.

There is!

It's called : "A Shield!!" +2 AC or ~10% overall less chance of getting hit is a pretty decent incentive.

If you're really pushing it, use a Spiked Shield (if you have the Dual Wielding Feat!)

I realise that you're probably talking about some feat that makes 1x1h do more damage (maybe combined with a requirement to NOT use a shield) and I think that falls beyond the scope of the "normal" rulebook and solidly into "DnD Next Figthers Handbook" or w/e it'll be called.
There they can lavish and explore duelist specialists (as I would call most forms of "1x1h and no shield") and others.

So please, spare me the condescension about loving dual wielding two medium weapons, humans can do it in real life, why can't they do it in D&D?
...
Why not just provide rules for anyone to dual wield whatever and make it a viable choice?


You need to spend a lot more time in prayer at the alter of "Game Balance".

There is a spectrum between simulationism/realism and "Game Balance".  There should not be one choice that is the undisupted "best option" (2 - 1h weapons vs weapon/sheild vs a 2h weapon).  Since we know pretty much for sure that they are not going to change the damage of any 2 handed weapons (in the name of "staying true to all previous editions"), they can't simultaneously allow you to wield 2 d8 weapons and keep that in balance vs a single d12.  Thus you are stuck with 2 short swords (2d6) being balanced against 2-handed weapons (1d12).

The problem with dual wielding was never the dual wielding.  It was the game mechanic that they introduced in 2e (IIRC?) that granted you extra attacks BECAUSE you were wielding 2 weapons.  This notion is now the defacto assumed default and if wielding 2 weapons doesn't give you extra damage/attacks then the grognards will start crying foul.  This in combination with the game balance issue above makes it very unlikely you'll be dual wielding anything bigger than a d6.

Frankly I like the 4e solution.  Everyone can wield 2 weapons (with no penalties), but just because you're holding 2 weapons doesn't mean you get a/an extra attack(s) (or do any extra damage).
So even with two feats, the average damage is only 1 point higher!  I guess this version of two-weapon fighting is actually awesome.  It gets my official seal of approval!



And is a trap.  You don't want Two Handed weapons to be EQUAL to Two Weapons in damage, because as you point out, Two Weapons has the added advantange of easily hitting multiple targets.  Not to mention feat support that allows them to increase in defense over and beyod armour (yes, it's 1 point of AC, but it's still ONE POINT MORE.)

I figure with the same amount of Feats, a two handed weapon user should do at least 25% more damage in a single attack.
I figure with the same amount of Feats, a two handed weapon user should do at least 25% more damage in a single attack.

I don't have a specific number in mind, but I agree.  Here is how I broke it down at one point:

Weapon & Shield: best defense
Great Weapon: best damage
Two Weapons: best versatility

Of course, that is the default, with no feat support.  I have no idea what feats will look like in the next packet, but my ideal feat support based on the current packet would be something like this:

Each group can use feats to duplicate the features of another group.  So, for example, you could take two-weapon fighting feats to increase your damage or increase your defense.  But there would also be feats to increase what you are already good at.  So a great weapon fighter could take feats to boost damage too.

But honestly, I think I agree with Kenjoon: the easiest solution is to just drop the idea that holding two weapons gives you a second attack.  Here is my idea:

You can freely wield any two one-handed weapons.  If your off-hand weapon is light, increase the damage of your main weapon by one step.  So, if you have a rapier and a dagger (nice classic combo), you will deal 1d10 damage.