While I don’t an issue with fighting in darkness being a straight roll, I like the emphasis idea. I’m just not sure how it plays out.
Advantage with emphasis: you roll 2d20 twice, keeping the best result out of each emphasis roll?
Or does emphasis only comes up in situations where advantage and disadvantage cancel each other out?
The idea is, Emphasis only comes up when Advantage and Disadvantage would cancel each other out. Any instances of Advantage or Disadvantage individually take priority over Emphasis.
So, for a practical example, let’s say your Drow character casts Darkness (and let’s say they do not have the Devil’s Sight invocation). As previously established, you would have both Advantage and Disadvantage on attacks against creatures within the darkness, which under RAW would cancel out to a single d20 roll, but under this house rule would convert to Emphasis. Now, let’s also say your drow character has the Lucky Feat. Under RAW, spending a luck point to gain Advantage would be pointless, since the Disadvantage from the darkness cancels out all instances of Advantage. Under this house rule, spending a Luck point while attacking in darkness would result in attacking with Advantage, because Advantage trumps Emphasis. So, say you attack and hit, but your target has a reaction that allows them to impose Disadvantage on your attack, so they use that. Now you’re back to Emphasis because the roll has Advantage from Lucky and Disadvantage from the reaction. And then let’s say your target has an ally who casts Silvery Barbs to give you Disadvantage. Disadvantage trumps Emphasis, so now you’re attacking with Disadvantage.
We are
functionally counting instances of Advantage and Disadvantage and giving you Emphasis only if the number of each is equal. But, we don’t have to track any actual numbers, just the trinary logic of which of three states the attack is in. And, as an added bonus, there’s never a need to re-roll, because all three states involve rolling two dice. The statuses just tell us which of the two results to select, so even if these instances of Advantage and Disadvantage are all being applied after you’ve already rolled the dice, you don’t have to back up and roll again, you just choose either the higher, lower, or furthest from 10 depending on the final status you determine the roll has after everyone has used whatever reactions they want.