Here are a couple of variant rules for social interactions. Their goal is to spread around who gets to be the party face, both by lowering the incentive for the character with the highest Cha to make every social roll, and by occasionally forcing other characters into the front seat.
Languages
One thing that struck me when watching The Bad Sequel is that:
- whenever there's an alien language, one of the protags can pretty much always speak it and translate for the others
- unless C-3PO is around, the translating protagonist is more-or-less randomly chosen
And I like this. It's simple and quick. It's no longer "everyone but the bard can safely dump Cha", since you never know when you'll be called upon to handle negotiations.
So here's a variant language rule:
All PCs, being widely-travelled oddball sorts, are multilingual, but language proficiencies aren't determined at character creation. Don't write down any proficiencies you might have from race, class, background or a high Int score.
When a character tries to understand or communicate with an NPC who isn't speaking Common, the GM decides the following:
- Is the NPC even capable of language? One GM might rule that a reanimated skeleton understands language, another might rule a skeleton magically follows its creator's commands but otherwise doesn't understand language. This is fine.
- Do outsiders share the NPC's language, or are they so culturally insular or isolated that this isn't possible? Obviously, secret languages like Druidic fall under this category too.
If the answer to both questions is yes, then the GM selects a single PC at random. Optionally, hirelings and the like can be included in this random selection process. This can be done with a bag of tokens, rolling a die and counting clockwise, whatever. I like the bag of tokens.
That PC can speak the language, perhaps not fluently, but enough to hold/follow a simple conversation.
Persuasion
There are no skills like Persuade, Intimidate, Diplomacy, etc.
You might decide to leave a Sense Motive/Insight skill in place. I would limit its uses to learning an NPC's emotional state, one of their ideals or bonds, or, in combat, judging what their immediate intent might be.
The player roleplays their character's pitch, then someone rolls 1d6 to determine the outcome. On a modified 5 or greater, they succeed.
The GM might raise or lower the difficulty. A Peaceful Villager might only need 3, a Haughty Archmage might need 7. Or the GM might apply the Powerful Enemies rule instead. This is meant to be simple though -- don't overcomplicate things trying to capture every nuance.
Modifiers to the roll:
- +1 if you have a relevant background
- +1 for a good social stat, e.g. 13+ in Cha. No further bonuses.
- +1 if you offer something of value*
- +1 if you appeal to one of the NPC's ideals, bonds, factional alignment etc.
- +1 if you act your heart out (can be hammy, doesn't have to be "good")
- -1 to 3 for demands that put the NPC at risk. -1 is "risk a parking ticket", -2 is "risk divorce", -3 is "be your torchbearer in the dungeon"
*Obviously the thing you offer needs to have value somewhere in the same ballpark as the request -- this is left to GM fiat.
Options
Use a Powerful Enemies rule if you like -- if the NPC has more hit dice than the PC, the difference is added to the difficulty of the roll. The reverse doesn't apply -- a 15th level fighter doesn't magically make every turnip farmer bend to their will. For 5e, use the difference in CR instead of difference in Hit Dice.
Certain NPCs may be immune to swaying the odds in particular ways, or may be more susceptible. Maybe a Magpiefolk gives you +2 to the roll if you offer a shiny geegaw of value, while a Angel gives you -1 to the roll instead, righteously furious that you would dare offer a bribe.
You can simulate regional language groups, loanwords, pidgins etc by putting an extra token in the bag when choosing who knows the language. This token represents whichever character, based on the GM's judgement, is most likely to know a language. e.g. the token represents the party dwarf when adventuring underground, the elf when adventuring in forests, and within the cosmopolitan City States of Arthea, the PC with "Background: Merchant". This isn't really a mechanical benefit, as any increase in one character's odds of knowing a language come at the expense of everyone else's odds. That is, don't make this a feat or anything.
I've presented this as a d6 roll-over, but feel free to reskin it to d6-roll-under, or modify this into a PbtA move or something. You could also multiply all the modifiers by 3 and use d20 roll-over, or use SotDL's boons & banes mechanic, whatever takes your fancy
Rationale
Yes, this means the polar Snow Elves and the Aquatic Elves of the tropical coral atolls probably don't speak the same "Elven" language. This is intentional.
I don't like how much weight 3e/4e/5e, or The Black Hack's d20 roll-under Cha, gives to possessing a high social stat. e.g. low-level 5e has a difference of about +5 (or +7 with Expertise) on d20, between a trained character with 16 Cha, and an untrained character with 10 Cha. All other factors (bribes, appealing to the NPC's beliefs, good roleplaying, etc) are typically handled with advantage/disadvantage, which doesn't stack.
This just gets worse as characters level up -- their proficiency bonuses increase, they may even find magic items that raise Cha beyond 20. For 3e D&D (faster scaling, stats don't cap at 20, magic skill bonuses are commonplace) the math is even worse, though Rich Burlew did write a nice, if crunchy, replacement Diplomacy rule a looong time ago).
So I want to reward clever manipulation and willingness to perform, but also allow a bit of room for characters being better at social stuff than their players, and not have the outcome be entirely DM fiat. Having a die result to point to, with really simple modifiers that are all worth the same 17% of the die spread, hopefully strikes the right balance for me.
Offering something of value is only ever worth +1. Why? Consider the following two examples:
- A stranger in the street offers me $10 to do some errand. Sure, I'll probably do it. If he offers me $10,000 for the same errand, he's probably a scammer.
- You're medieval nobility. A representative of the Pope says if you go on crusade, you'll be absolved of your sins (and oh, how you've sinned). This is theoretically a reward of infinite value, the difference between paradise and eternal suffering, yet not every nobleman went and did a Richard I. Humans are not rational appraisers.