D&D General Taking Advantage of Advantage; a new mechanic pitch

[Xeviat]

Of all the additions in 5.5, my absolute favorite is Cunning Strike and it's related abilities. Rogue and Barbarian both have features to give up one of their advantages (advantage or sneak attack dice) to gain attack riders. Paladin technically has a similar ability, with Divine Smite vs other smites that do less damage but have additional effects. Monk kind of has a similar ability, with their additional unarmed attacks and the basic ability to swap unarmed damage for trip, push, and grab.

In thinking about a similar ability for rangers, I came up with an ability mechanic that I'm itching to use.

What if there were abilities that gave you additional effects if you attack with advantage and both rolls are high enough to hit? I think there was a Book of Nine Swords maneuver that did something similar, and there was Rend back in 3E giving extra damage if you hit with both weapons with TWFing. It could even be a trade off ability; if you attack with with advantage, you can declare before your roll that you're "Taking Advantage", which means both attacks need to hit but you gain an additional effect.

What does the math end up looking like?

Attack Roll Needed​	Hit %​	Advantage Hit %​	Taking Advantage Hit %​
1​	100.00%​	100.00%​	100.00%​
2​	95.00%​	99.75%​	90.25%​
3​	90.00%​	99.00%​	81.00%​
4​	85.00%​	97.75%​	72.25%​
5​	80.00%​	96.00%​	64.00%​
6​	75.00%​	93.75%​	56.25%​
7​	70.00%​	91.00%​	49.00%​
8​	65.00%​	87.75%​	42.25%​
9​	60.00%​	84.00%​	36.00%​
10​	55.00%​	79.75%​	30.25%​
11​	50.00%​	75.00%​	25.00%​
12​	45.00%​	69.75%​	20.25%​
13​	40.00%​	64.00%​	16.00%​
14​	35.00%​	57.75%​	12.25%​
15​	30.00%​	51.00%​	9.00%​
16​	25.00%​	43.75%​	6.25%​
17​	20.00%​	36.00%​	4.00%​
18​	15.00%​	27.75%​	2.25%​
19​	10.00%​	19.00%​	1.00%​
20​	5.00%​	9.75%​	0.25%​

OK, so at the standard 65% chance to hit, voluntarily doing nothing unless both attacks hit would be a huge drawback. "If both attacks hit" as a bonus could be a big gain. It's about half as likely as the advantage hit, so a feature could offer double the damage of a normal on hit effect, maybe adjusted up a little since the feature would only work with advantage (though Rogues and Rangers can get advantage easily, and 5.5 isn't hard to get advantage.

What could you see doing with "if both rolls hit with advantage"?

 

[Charlaquin]

Kinda reminds me of the crit confirm roll in 3e. Not the same of course, but a bit reminiscent. Deciding that you’ll miss if you don’t hit both is pretty harsh, but as a randomized way to determine when an on-hit ability procs, it sounds super cool! I’d probably use it for stuff similar to Cunning Action - extra debuffs that apply to the target like conditions, rather than just more damage.

 

[Shardstone]

Advantage can be used in creative ways.

• Advantage can activate certain rider effects on a d20 test or damage roll
• Advantage can be spent to generate special modifiers or effects on a d20 test or damage roll
• Advantage can be transferred under certain conditions
• Advantage can create certain shields or buffs for a character for as long as they have it
• Disadvantage can allow for certain shields or buffs for a character as long as they have it

So right there we have five different ways that we can get creative with advantage. By working these into class features, we can begin to create a fuller game. Some examples:

• When a Paladin has advantage on an attack roll, they reroll any smite damage dice
• When a Cleric has disadvantage on a saving throw, their god provides them with temporary resistance to any damage suffered
• When a Barbarian makes a grapple check with advantage, they can choose to deal force damage equal to their level if the target fails their saving throw
• When a creature rolls with advantage against a Sorcerer's spell that used metamagic, the sorcerer regains the sorcery points they spent

And so on. These mechanics are just idea, so they may be rough or unusable, but they exist to show you the general idea.

5E has a lot of design space like this that is wide open and rather untapped by both first and third party designers.

 

[Li Shenron]

​	​ OK, so at the standard 65% chance to hit, voluntarily doing nothing unless both attacks hit would be a huge drawback. "If both attacks hit" as a bonus could be a big gain.​

Good design exercise.

If you have to choose before rolling whether to "do nothing unless both attacks hit", it means converting advantage to disadvantage (in terms of probabilities only, not counting fully as disadvantage) in exchange of an extra benefit on success. So yes it's a significant drawback and can be worth a significant benefit.

 

[Daztur]

Good design exercise.

If you have to choose before rolling whether to "do nothing unless both attacks hit", it means converting advantage to disadvantage (in terms of probabilities only, not counting fully as disadvantage) in exchange of an extra benefit on success. So yes it's a significant drawback and can be worth a significant benefit.

Yeah I don't mind the specifics of the rules, but it seems like it's just a fancy way of saying "give yourself disadvantage in order to do something special."

 

[GMMichael]

Well you have a 5% chance to crit by rolling 20. It looks like odds of Taking Advantage are generally higher, so I'd expect a reward for it that's less significant than a crit. Furthermore, the point of the Advantage mechanism is to streamline the game, and adding rules to it undermines that . . . but could still be fun.

 

[Zaukrie]

I think there is definitely interesting space here! Good idea, and I'll give it thought for sure.

 

[Xeviat]

For some reason I didn't realize voluntarily upping the ante made Advantage turn into disadvantage. Considering I've long been okay with called shots being disadvantage to gain a benefit, you think I would have noticed that.

I've already pitched to my group the following house rule for Foe Slayer Ranger 20th: When you attack a target of your Hunter's Mark (reminder, level 17 gives advantage to attack Hunter's Mark targets) with advantage, your attack is a critical hit if both advantage attack rolls hit.

My quick test shows a 9 dpr increase, which is comparable to the jump from 19th to 20th barbarian using brutal strike (which is also a give up advantage effect).