Part of an ongoing series of 5e Rules notes.
This is actually an interesting and (at my table) unused game mechanic: dealing with skill checks as a group, rather than as individuals. It not only can save time, but it can get around some of the problematic aspects of Skill checks.
Group Skill Checks
The rock chimney needs to be ascended — not by an individual, but by the whole party.
The goblin encampment needs to be snuck past — not just by the rogue, but by that jingling oaf of a fighter, too.
The suspicious guard is eyeballing everyone who passes — and the whole party has cultist robes, hoping they can slip by.
5e includes a method for groups, as a whole, to make an Ability or Skill check. As laid out in PHB 175:
To make a group Ability Check, everyone in the group makes the Ability Check. If at least half the group succeeds, the whole group succeeds. Otherwise, the group fails.
The idea here is that more experienced or skillful players are helping the less experienced or skillful ones to succeed.
“Put your feet right where I put mine … there you go, that’s it, great!”
“Watch out for that stick there — don’t step in it because it will snap and make a loud nose and ruin our chance to sneak by.”
“I wish you peace, diligent guardian of the temple, as do all my friends, riiiiiight?”
Group checks are useful where all the characters are
(a) doing the same thing, against
(b) a challenge with a single DC value, and will
(c) succeed or fail as a group.
Some examples:
- Does the group get through a swamp without running into quicksand or a similar hazard? Roll as a group on Wisdom (Survival) vs a DC.
- Does the group sneak by the observation post without being heard? Roll as a group on Dexterity (Stealth) vs a standard passive Perception value.
This mechanic works less well when there are multiple values in the challenge/opposition, and where an individual can potentially shine.
Their applicability, though, is limited. The mechanism could be used, in theory, for spotting traps, for example, but it makes a lot more sense that the rogue is looking for traps and that their Perception is what makes or breaks the deal, rather than have them succeed personally, but then have the group fail as a whole because presumably a bunch of people did poorly and distracted the rogue from a trap they should have found.
Helping someone else
This is related, but similar. Note that someone can do a Help action in combat to give a person making the Skill or Ability Check do so with Advantage (if the helper can explain how it is they are helping, of course). That’s how this all functions tactically in a battle.
The Ranger’s background gives her a lockpicking ability to Help with — not as good as the Rogue’s, who’s frantically working with his tools against the lock, while the other party members fend off the guards, but good enough to offer useful advice, hand the correct next pick to the Rogue, and overall give the Rogue an Advantage in trying to get the door open.
In theory, it works that way for other activities. So, under the rules for Working Together:
Sometimes two or more characters team up to attempt a task. The character who’s leading the effort—or the one with the highest Ability Modifier—can make an Ability Check with Advantage, reflecting the help provided by the other characters. In combat, this requires the Help action (see chapter 9).
A character can only provide help if the task is one that he or she could attempt alone. For example, trying to open a lock requires proficiency with thieves’ tools, so a character who lacks that proficiency can’t help another character in that task.
Moreover, a character can help only when two or more individuals working together would actually be productive. Some tasks, such as threading a needle, are no easier with help.
So, for example, when searching the room for something, a pair is actually better off with the best-Perception person doing the search, and someone else assisting them (for Advantage) than both people doing the search roll (because rolling with the highest Skill twice gives you a better chance than rolling once with a high Skill and once with a lower one).