They stole my my help as a bonus action idea...
This is pretty vague, but zero for both? What kind of party goal? Why are you hinging anything important on an all-important single roll? Yuck.
Again, this is pretty vague but it sounds like poor application of skill checks. If you are going to make a McGuffin so important, don't place it in the hands of fate by hoping someone makes a skill check to acquire/achieve it. This is just poor encounter design.
Your party decide to make use of their disguise and forgery skills to infiltrate something. You fall your disguise check. What happens? Does your plan to infiltrate still succeed? Then the guard checks your papers. You fall your forgery check. Is your plan still working after that? Then you fail a deception check. Are you still on track for getting in?
Compare the typical results of those three failures on your plan with missing attacks in combat if your plan had been to simply kill your way in.
Okay you failed your try to go straight through the guard checkpoint plan... Why is that the only possible plan? How about actual stealth infiltration. You know wait for night, climb to a high window, go in that way.
How about bribing one of the known castle suppliers to smuggle you in on a cart?
Yeah you failed to achieve your goal on the first attempt. The cool thing about failing those skill checks is that unlike combat the added up failures don't lead to death, just an opportunity to approach your problem in a different manner. By avoiding combat you've ensured that you will likely get another chance to try and accomplish your goal. Just attempting to kill your way in had the unfortunate side effect of making death a very real possibility.
Because the rules of many games--not just 5e, and not just D&D for that matter--often make future, alternative attempts dramatically harder due to failed previous attempts, even when the two are notionally distinct e.g. failed deception/forgery leads to heightened guard presence. Further, Stealth is almost always even worse than social skill uses: everyone infiltrating has to roll it, and usually must do so multiple times to avoid detection. Iterative probability essentially guarantees that that will fail sooner or later. 5e is ever-so-slightly better about that, since it advocates the use of group checks, but even its rules (from what I can tell) do not really solve the problem of "way, way too many DMs call for too many iterative checks, thus semi-guaranteeing failure."
Also, uh, Stealth is actually a Dex skill, so we've kind of circled right back around to "Rogues want Dex."
How and where was this "knowledge" acquired? It is not merely common knowledge who supplies the castle, and if the security is serious enough that notarized documentation is required to enter, I imagine this bribery attempt is going to be difficult...and will still require multiple Stealth checks from the whole party, and group checks don't seem like they would cut it in this case (since the guards need only find *one* hidden stowaway to raise their suspicions to an unacceptable level).
It sounds to me like you've been relatively lucky as far as DMs go. My experience has not been so good--failed attempts at an action have a bad habit of making all other means of addressing the situation harder, until there are no alternatives left at all (which can be as quick as "you failed your first attempt"). No skill rules I've ever seen--not in 4e, not in 5e--actually address this, particularly the iterated probability issue.
And I suppose that the consequence of failed impersonation and forgery is flowers and sunshine?Just attempting to kill your way in had the unfortunate side effect of making death a very real possibility.
And I suppose that the consequence of failed impersonation and forgery is flowers and sunshine?
My guess is this: either your games are weirdly devoid of consequence or you are making success at these skill checks either very easy or automatic much of the time. Which is still devaluing stats.
Ah, okay. Now I see what you were trying to say.Your party decide to make use of their disguise and forgery skills to infiltrate something. You fall your disguise check. What happens? Does your plan to infiltrate still succeed? Then the guard checks your papers. You fall your forgery check. Is your plan still working after that? Then you fail a deception check. Are you still on track for getting in?
Compare the typical results of those three failures on your plan with missing three times in combat if your plan had been to simply kill your way in.
Ah, okay. Now I see what you were trying to say.
No, those situations are not TPK/game enders. They are setbacks. PCs have setbacks all the time.
The disguise check didn't work. Now they need a new plan. Same with the forgery check.
You made it sounds to me like a couple checks fail and the adventure is over. That doesn't happen in my games.
I believe that it would be closer to a couple of failed checks and combat starts. Meaning that combat is a very important thing in the game.
Beyond that I have to determine what the code of law is here for trying to forge an illegal document, and weather or not some corrupt noble gets wind of your attempt, and springs you himself so he can attempt to employ you to forge something for him. It's really easy to spring you when he's technically a high ranking member of government and can just quietly help your release.