Involved Skill Check System

I’m resigning myself to the fact that most people just want to play 5e D&D, so I should probably be making sure that what I make is 5e compatible, if at all possible. Here’s a shot at adding a system for resolving complex problems in a slightly more dynamic way. You can use this for social negotiations, climbing cliffs, disarming complex traps, sneaking through a temple full of cultists, or whatever else you’d like.

The Core Mechanic Whenever you have a skill check trying to resolve a problem, you set two numbers: a Difficulty/DC rating, which is the minimum number you need to roll to make progress, and a Complexity rating, which is sort of like the problem you’re dealing with’s HP. Roll the skill check normally. For each point you beat the DC by, lower the Complexity by one. If you reduce the Complexity to 0 you fully succeed--congratulations! However, if you fail to beat the DC or don’t beat it by enough to wipe out the Complexity in one go, the problem then gets to act/you get hit with a Complication/something goes wrong. You then respond to or suffer the effects of the Complication, and if the original problem is still relevant you can take another shot at it. Repeat until you’ve either succeeded or things have gone wrong enough that you have entirely new problems to deal with.

You can think of this almost as a reformatting of combat--you and the problem take turns attacking each other until either the problem is solved or you’re defeated. It’s meant to let some non-combat situations have a bit more weight and chance for partial successes than the normally binary skill check system would allow for.

It’s also meant to hew as close to the existing 5e skill system as possible. If you set the Complexity to 0 you’re basically just using the default skill system, and most of your challenges should probably be Complexity 0.

I tried to keep the above description as short as possible, so let’s unpack it a bit/offer some additional advice/add a few extra rules:

Complications Severity

A Complication occurs whenever you roll on a problem and fail to finish it off. They should flow from common sense and the situation at hand, and I’m intentionally avoiding giving them much mechanical definition. That’s not super helpful, though, so here’s a bunch of non-binding advice on how to think about them.

Problems can be thought of as having a severity rating of the Complications they’re likely to produce: Safe, Risky, Dangerous, or Deadly. If a player wants to know the severity of a problem before they roll you should probably tell them. If the outcome of a problem is unknown (unlocking a treasure chest that may or may not be trapped), just tell them that instead--maybe they’ll choose to gather more info before they act.

Safe Complications are ones where the worst case scenario is generally just that you won’t be able to try again, or that you’ll waste time getting nowhere. A good default result of failing to finish off a Safe Problem is that it becomes Risky--you’re fine for now, but continuing the conversation might make the guard suspicious/you’re starting to feel overheated as you hike through the desert--no mechanical penalty this time, but from now on failing a roll might inflict HP loss or Exhaustion.

Risky Complications cause short-term problems. The farmer you’re talking to gets mad and doesn’t want to talk to you any more. The king you’re asking a favor from asks you something in return. The raging fire you’re trying to put out spreads to a new location. If you’re taking damage it’s probably equivalent to one attack from a level-appropriate monster.

Dangerous Complications cause long-term problems. The farmer decides you’re devil-worshippers and raises up a mob to come after you. The king tells the guards to throw you in prison. The fire causes the building you’re in to start collapsing, cutting of your way out. You contract a status condition that takes you out of the fight--paralyzed, confused, or asleep. You can break out wildly level-inappropriate damage dice at this level.

Deadly Complications are instant death or permanent debilitation. You fall into lava. You’re crushed under the giant block. The demon rips your soul from your body. Medusa turns you to stone. Problems should basically never start out at these stakes--if you’re shimmying along a cliff over a bottomless pit a failure should be you losing your grip and starting to slide down, not you instantly plummeting. That gives you a chance to come up with a goofy plan or burn some resources to save yourself, instead of just instantly losing your character.

The entire point of having a Severity system is so that you don’t need to think up exactly what the outcome of a failure or partial success would be for every single roll. If there’s an obvious outcome, you can just say that instead of picking a Severity. This is all to help make life easier, not give you extra busy work.

Picking Complications

Some good Complications might be: take damage, take a status effect, lose an opportunity, lose an item, a new problem occurs, things get worse, roll on a table, a fight breaks out, something is demanded of the player, an NPC makes an ultimatum, the player has to make a choice between two possible Complications, the severity escalates. Ultimately, though, just go by what makes sense given what’s been established so far.

Especially fun are Complications that force a response from the players--rather than hitting them with damage or a status immediately, throw a new sub-problem at them that they need to be able to have an answer for; if they have the answer that’s good, but if not hit them with an even stronger effect. High stakes but with chances to save yourself is more fun than a lot of little unavoidable attrition hits. In a negotiation, have the NPC ask the player an inconvenient question. Climbing a cliff, have the rope fray slow enough they can leap to another or cast a spell. Set up threats, then give the player one or more turns worth of actions to diffuse them.

Complications can and should often involve rolls. Failing a Safe check in a dungeon might result in burning enough time to trigger a Random Encounter Roll. Getting pricked by a hidden poison needle in a treasure chest might trigger a CON save. A good wilderness exploration Complication might be to roll to avoid becoming lost. Your hireling makes a morale roll. There’s a 1-in-10 chance per Complication that the fire reaches the gunpowder and the ship blows up. You can temper the severity of an outcome somewhat by giving the player an extra chance to avoid it.

Should failing to hit a DC trigger a worse Complication than simply failing to finish off the problem? Sure, why not! If you don’t have any better ideas, hit the player with both an immediate Complication AND raise the Severity of the problem on a full failure, but only do one OR the other on a partial success.

Should a problem hand out the same Complication each round or do new ones? That probably depends on the situation at hand. It makes sense that if the problem is a room filling with poison gas that you’d have the same Save vs Poison Damage or whatever each round, but in a negotiation with a king it’d make sense to throw all sorts of stuff at the players--unexpected requests, interruptions, breaches in etiquette, etc.

Setting Your Ratings

You can write out these types of problems as DC #/# if you want, using the first number as the Difficulty and the second as Complexity. So DC 15/5 would be a Difficulty of 15 and a Complexity of 5. Complexity is a long word and writing it a bunch seems annoying.

I’m going to encourage you to set your DC and Complexity both to numbers divisible by 5, just to make the math easier. 

For lots of problems, a Complexity of 5 is probably plenty. 15/5 means a low-level character with a +5 to their roll has a 50/50 shot of getting a partial success and a 25% chance of succeeding outright. That feels about right as a default quick problem, like jumping across a chasm or a classic reaction roll-type situation.

A big scene-consuming problem that the entire team is working against might have a Complexity that is much higher--50 or more.

Possible Modifications

I’m tempted to change the rules so that you reduce the Complexity by 1 if you hit the DC and then by an additional 1 for each 5 you beat the DC by--the math seems a little easier than subtracting the DC from your roll and the result from the Complexity. That might create weird dead zones in the dice results, though. 

5e skill checks are not nearly bounded enough. This system breaks down a bit when you have one player with a -1 to a check and another with a +17/minimum roll of 10. This was already a bit of an issue in 5e, and if anything it helps a little--a mid PC can succeed at what an optimized PC can, it just takes them longer and they run into more complications--but it’s still a problem. 

My idea for a solution: When rolling a skill check you add your Stat bonus to the roll. If you have proficiency in the skill, roll one extra d20 and take the higher. If you have expertise, roll a third.s This stacks with advantage/disadvantage.

This fix makes low level characters a lot more competent--proficiency moves from being a +2 to the equivalent of a +5--while making high level ones a bit less--from a +6 to a +5ish, but also weakens expertise a bit--you get some diminishing returns from all those extra dice. It also makes the range of possible DCs way smaller--the highest a character could ever roll would be a 25, but a character with proficiency and a +0 stat is still going to roll over DC10 75% of the time and is going to beat DC21 0% of the time. It means you’d probably just want to be using DC10 or DC15 for most situations, setting difficulty more with Complexity. That sounds fine to me, but I should test it out more.