I want to argue that combat is the only part of the game in which the default should be reaching for dice and relying on mechanics. That in ALL other parts of the game we should first try to resolve things through narration/storytelling, and only roll dice as a last resort to resolve real uncertainty. Or, at least, that's how I personally would like to play. I believe that, outside of combat, rolling dice should follow this pattern:
- The player declares an action
- If the DM decides the outcome is uncertain, and there is a real cost to failure, the DM may call for a roll
- The DM tells the player what the roll will be, including DC, and what the cost of failure will be
- The player then has the option of not taking the action
I largely agree with this though I'd add some caveats:
1st Caveat. This is dependent on system and play style. If one is playing a style of game that's largely about tactical combat and character building where non-combat actions need to be pushed through quickly and are a lesser/smaller part of the game it's fine and good to have a robust system of mechanics (based on char building really) that both fill in the narrative space between set-piece tactical combat and encourage char builds that aren't entirely focused on being combat optimal.
2nd Caveat This structure is not used for EVERY obstacle or encounter outside of combat. Things like traps and surprises may simply force a roll ... a saving throw so to speak. Furthermore and related it's good to have several basic sets of mechanics that the referee can declare will be used to resolve general types of obstacles. For example I would use a "Save vs. Paralysis" (the old style save unrelated to stats) as a way to avoid getting caught in an avalanche, but might use a DEX check to leap over a chasm, potentially allowing "climbing/acrobatics" to be used by a PC with that skill.
In general though I think it's key in an exploration focused game, especially if one is using a higher lethality set of rules for the referee to A) question players who are about to undertake a declared action that seems odd, especially dangerous or incongruous with the situation B) Give an example of how the mechanics will work if mechanics are involved prior to the player committing to actions. This is because I assume PC competence, and acknowledge that my descriptions may be incomplete, confusing or that players may have been distracted.
Example: There's an 80' deep well and a player says "My character is just going to hop down and have a look." Obviously this is weird - but to the player they may have missed how obviously deep the well is. I would stop and confirm saying something like "You can't see the bottom of the well even with the lantern shining down it and you will take 1D6 per 10' of falling damage" ... because the PCs are going to shine a light down there before leaping. I don't need to be antagonistic and that includes concealing info. As an "old school" referee the world and narrative are entirely in my control. Lightning from the heavens can kill the PCs if I desire etc. I designed the dungeon, and it could always be harder. I have no need to hide the details of challenges - because I want the players to have all available information to try to solve them.
Another reason this is useful is because it increases trust between players and referee - meaning paradoxically that the world can actually be harsher, because the players accept that the referee is being honest and not hiding information from them. The puzzles/obstacles/challenges are about what they are intrinsically rather then a game of rules manipulation or finding the flaw in the referee's description. I actually include a lot of challenges that I don't have immediate answers to in my dungeon design (at least for my own games) because players are quite good at figuring out ways around/through them. To do this though it really helps if the players trust the referee is being fair - that if they come up with a plausible scheme the referee will first give them mechanics (replicating the characters ability to judge the intangibles that we can't describe completely) and allow success if the idea is good/or they beat the odds.
And, by the way, "you can't try again" is not a cost of failure, at least by my definition. If you try to pick a lock and you fail, the door is still locked; the game state hasn't changed.
Litmus Test: if the DM's only tool for preventing everybody in the party from trying is by declaring (unrealistically) that only one character is allowed to try, then clearly the penalty for failure is insufficient.
Fair - My penalty is almost always the passage of a turn. Turns passing means random encounter checks, which mean burned resources for no treasure (almost always). I don't think this is an absolute though, there are times when only one PC can try or there's only one chance to try. Lassoing a fleeing horse or something else momentary comes to mind. Disarming a trap also comes to mind as failure may trigger it.
I think the point about any of these procedural questions is that they are general, but not absolute. The referee exists not simply to set to clockwork of the rules in motion and enforce procedure, or even to decide when a specific rule applies -- but also to decide when a situation calls for an ad hoc adjustment to rule and procedure.