Beyond advantage and disadvantage

 Where the increasingly popular mechanic of advantage and disadvantage is discussed and dissected and an improvement proposed.

A quick trip down memory lane.

We’ve all been there. It’s 2011, Friday, well past midnight, it’s the sixth fight of the session and your eighth beer bottle is already emptying. The battle with the lich priest and his deathknight bodyguard is raging and your barbarian prepares to axe the bastard to kingdom DON’T come. You roll. It’s a 7. You add your attack bonus, now it’s 24. Good, but not good enough. “Wait!” you exclaim, “The ranger is flanking him for +2, she has a feat that lets me share her favoured enemy attack bonus of +4 and I am on high ground for +2. That’s it, that’s 30! I hit!” The DM looks at you from across the table, a grin across his face. “That’s a 32 you drunk imbecile, and you are power attacking, for -4! And the high ground bonus is +1! That’s a 27, still a miss.” Frustrated and with the threat of a TPK looming overhead you search your character sheet for every possible bonus you can find. After five long minutes of searching you accept the result. You missed. The ranger who has been waiting for you to end your round is understandably frustrated.

The present

Its 2021 and the newest edition of tHe wOrLd’s mOsT pOpUlAr gAmE is a huge success. The advantage and disadvantage system is declared the end of history in rpg design. No more will you have to count countless modifiers and humiliate yourself with failing at first grade maths. No, you only need to see if you have advantage and roll dem bones twice. Hoping that your arithmetic shenanigans will be put to an end the party invites you to play with them again.
Lamborgimli, your half-dwarf, half-centraur, 100% warforged artificer is lifting his clockwork axe to decapitate the prone, blinded, poisoned, cursed hobgoblin in front of him. Prompted by the gm you roll two dice. “Miss!” he proclaims as he facepalms. Two rounds later the hobgoblin is still on it’s last legs, your face has turned orange from it’s frustrating AC and you roll once more. The first die is a 7 but the second one is a 20. “YEEEEEEEEEES!” You jump from your seat ready to roll your damage dice twice. “Actually, no” the gm interrupts you. “He puked on your feet last round and now you are on slippery footing. Advantage cancels disadvantage so...”

The shortcomings of advantage and disadvantage

Go to any rpg community online, the vast majority of the people are going to applaud the elegance of the advantage/disadvantage system. And I would be arguing in bad faith if I disagreed here. The days of 3.5 and Pathfinder and thankfully well past, no more will one have to count half a dozen modifiers of different magnitude just to resolve a single roll. And that complexity added little to the game while reducing it considerably. It would be equally disingenuous however if I too celebrated the oversimplification of Advantage and Disadvantage. Namely due to the following:

a. The eradication of stacking benefits removed tactics from the game. It doesn’t matter if you recklessly attack the prone, poisoned, blinded foe. Each and every one of these conditions results in precisely the same result. You roll two dice, you pick the best. And god forbid a possible condition that would impose disadvantage upon you. Then nothing else would matter.

b. The mathematics of the implementation result in characters being unable to succeed at anything they couldn’t before they sought to improve their situation. Consider this, any non combat roll of DC 21 is impossible for someone who rolls with a +0 mod. Now what if the same character put effort in improving the conditions of the roll? Unless the referee decided that such an improvement actually reduced the DC of the task it still remains impossible.

(Note: I understand that this can be a controversial take since any DM worth his salt would make a ruling in favour of said character. However, here we are discussing the merits of the system and not the one running them).

Design goals for an improved system

And what can be done you might ask? Isn’t there any way to fix the advantage and disadvantage system? Of course there is. We need to address the aforementioned issues. Every instance of advantage or disadvantage counts. This is superior to the modifier system of the previous editions because you only need to count them, not take their magnitude into account. Then instead of rolling d20’s you add (or subtract) a dice of varying size. The system is presented more technically below.

The proposed solution: Advantage or disadvantage die.

- If a roll is made with advantage 1d4 is added to it.
- If you have multiple sources of advantage increase the die size by one for each source beyond the first. The dice size chain is the following 1d4 → 1d6 → 1d8 → 1d10 → 1d12. In the rare case where there are more than five instances of advantage the Game master should consider granting an auto-success.
- If a condition significantly benefits the chances of success it provides superior advantage, meaning that you roll a d6 instead of a d4 or that you improve the dice chain twice. Keep in mind that such effects should be kept to a minimum as they deviate from the original design goal of counting sources and not magnitude
- Disadvantage works in a similar way but the dice result is subtracted instead of added.
- Advantage and disadvantage cancel each other out.

Further thoughts and considerations

- One of the interesting byproducts of advantage and disadvantage is the increase or decrease of critical hit chance. My instinct tells me that adding half the result of the advantage dice to the natural d20 roll and treating any result of 20+ as a critical is going to lead to interesting results. I also like that disadvantage makes it impossible to critical.
- One could alternatively recommend a system where each instance of advantage or disadvantage increases the roll by a fixed number +1 or +2. This can also work however dice are chaotic (therefore welcome) and they model the diminishing returns of further benefits.
- A note on the point above. Diminished returns could be handled by a table where the first instance of advantage provides a +3 increase a second a +5 a third a +6 which could also work. This is something I would like to playtest.
- Finally, there is a trend in post-D&D 5e games especially Lancer and Shadow of the Demon Lord to use boons and banes in lieu of advantage and disadvantage. If you have any ability or condition that improves your chances you roll an additional d6. If you have N sources of advantage you roll Nd6 but always keep the highest result. I like this, it is elegant and vastly superior to advantage and disadvantage, however the purpose of this blog is to discuss new ideas and not iterate on older ones.

PS.: At some point in the future I plan to make some a post with the maths behind the system presented here.

fin