Maybe untrained skills could have a DC limit on checks that can be even attempted, a limit like e.g. 15 (hence lower than the max roll result)?
This was suggested WAY back in one of the early columns by MM, but the problem is it creates a 'two tier' system where either you're trained or why bother. What happens when nobody happens to be trained in some skill? Even in 4e with its short list of skills chances are one or two of them won't be represented by any PC with training.
I voted for stat + skill + roll, but I also strongly like stat + roll, gain advantage if skilled.
Problem is, with the latter you can get some weird results where the talented (high stat) noob outperforms the skilled artisan, and I don't quite like that.
I have however a long-time issue with characters using untrained skills...
Sometimes I just don't like that ALL PCs get to roll. Just think about it: if you call for a Listen check to notice something and TWO PCs can roll the check, it's a little bit like one PC rolling with advantage, because one successful roll is enough. Now just try to figure out to what kind of advantage is equivalent the case of FOUR or more PCs being allowed to roll Listen for the same instance.
This is something I would totally like.
Those who aren't trained just don't bother, unless the check is basically a save (so they better try even if the chance is low, such as in the case of a Balance check) OR unless the check is easy like low-level challenges.
We have bounded accuracy for combat, why shouldn't we have also bounded accuracy for checks? Why should we always have to assume that low level PCs struggle to jump a 10ft pit, and high level PCs never have an issue with that? Personally I totally hate systems where all PCs automatically get better at doing everything.
So going back to your questions?
Q1: Why bother if you're untrained?
A1: Don't bother. This is exactly what I want: that those who aren't trained don't bother, because if they bother it means soon they'll figure out that it's always worth that all PCs try their luck at every Knowledge check or Profession check, Listen/Spot, Survival, Search, Track etc and every other skill the results of which affect the whole party and failure doesn't carry consequences.
Q2: What happens if nobody has skill X?
A2: A wonderful thing happens: that the party has to find another way to solve the problem! Once again, I hate games where the party covers everything, and I hate adventures where the DM requires one and only one skill or ability in order to continue. That's bad adventure design, thus if nobody has skill X and there is no other way to continue the adventure, this immediately shows the DM is a bad DM.
How do you go if you feel the opposite about these two?
1) You can always house rule that everybody is trained at everything, so everyone can always try the check. This is much easier than having a default where everyone can try everything and then having to figure out how to house rule which skills should allow this and which not, and with what limits.
2) You can always grant everybody bonus skills so that the party covers all the skill list and more. This is always easier than taking skills away.
edit: Also notice that at the moment the 5e system in fact IIRC already has some embedded limit of DC25. That's the highest DC you can beat with a skill check if you're untrained, because (without magical aid) you're bound to max 20 in any ability score thus +5 in bonus, therefore you're never going to roll more than 20+5 unless you're trained in the skill. Perhaps this is going to be good enough for my purposes, but at the moment it still feels quite high to me.
I voted for stat + skill + roll, but I also strongly like stat + roll, gain advantage if skilled.
Problem is, with the latter you can get some weird results where the talented (high stat) noob outperforms the skilled artisan, and I don't quite like that.
In the end, I think I'd actually prefer stat + skill + roll, gain advantage with the roll if skilled. Max the skill bonus to +5 and have it mean more than be "just a number" - go with the old guild rankings; initiate (+1), novice (+2), journeyman (+3), master (+4), grand master (+5). If you aren't of the right "rank" when making a skill test, you suffer disadvantage - negating the advantage you normally get for being trained in the skill. Adhocing the appropriate rank (i.e., where the DM doesn't deliberately set the level) might involve, say, subtracting 12 from the DC (so a DC 15 skill challenge would be a "Journeyman (+3)" rank test).
Rogues would still get their "skill dice", allowing them to add, say +1d6 to a given skill roll.
Group rolls and trained only skills.
...
There should be a bonus. But how much? Group rolls should be ingrained in the system completely. Some possibilities:
Two issues that are valid in any skill system.
Group rolls and trained only skills.
Group rolls need to be a standard rule and not some sort of poorly thought addition. They need to be right up front and easy to do. I'd like to see something where a group of 8 orcs can make a single roll to spot the sneaky halfling. There are a few issues at work here. As construed currently, there would be a lot of contested rolls, hide/spot and move silently/listen. This is very unwieldy and would be nice for both sides to make one roll and resolve the action. The other and most dramatic problem is the contested roll system. Opposed d20s are very swingy (I wont go into detail here but see my arguments in this thread). Then the heart of it is how do you fairly resolve many rolls all under one roll fairly, taking into account many factors (ability, skill, circumstance etc.). What happens when multiple people gang up on any roll? There should be a bonus. But how much? Group rolls should be ingrained in the system completely. Some possibilities:
- Highest skilled person rolls with advantage
- Lowest skilled person rolls with advantage
- Highest skilled person rolls, each other person rolls vs a DC then if successful adds +2
- Highest skilled person rolls, each other person adds +1, to a maximum number of people based on the task
- Like flanking in some way... which is in essence a group roll...
Trained only skills are tough. Not everyone is a surgeon. Certain skills people should have almost no ability to roll in. The rules can be tricky though because if you were a surgeon, you would know a lot of ancillary things about medicine. So imho, to model a system like this there should usually be a root untrained skill and then add the surgeon on top. So for instance, first aid, might be the root skill and then surgery an adder. The surgeon adder would unlock new uses of the first aid skill. In this way, the specializations to skills could come in from a module for those who wanted to use them.
There is one other type of rolling of checks that should be written right into the core: multiple skill rolls to complete a task. Some of these are obvious. Make multiple checks to climb a large cliff (distance divided by climb move rate). But what about a very complex lock, you might need multiple successes. What about banging a door down you might need 3 successes to knock it down (either from multiple people or stacking them round after round by bashing into it). Lifting a heavy slab might require 2 successes (2 or more people making a STR roll each round).
Multiple successes could be a way to handle group rolls too, in theory. Everybody rolls their check if you get a certain number of successes in the group then you are successful... Hmm have to think about how that would work...