When do individual ability checks become group ability checks?

Question

In the section Working Together, the basic rules state:

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, “Combat”).

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.

I understand that this happens when the group can, and will work together to do something, but I'm wondering about the limitations of these definitions.

For instance, in a game, our characters had to climb horizontally a porous wall for ~150 feet. Below that wall, 100 feet of void then the sea. Some characters were reluctant doing this as their athletics skill is the lowest, going in the negatives. The other characters convinced them to do it anyway, arguing they'd help. So the characters all attached themselves to a rope and started the climb. The help promised by the other characters was under the form "put your foot here", "put your hands there", "pull your weight in your hands" and other advises like that. Individual tests were used all the time. After 50 feet, the whole party was swimming in the sea.

After the session, I was wondering whether I should have asked the DM if a group check should have been done. Our DM never ever uses group checks as defined in the quoted part, and I'm wondering whether he knows about them. Given that we've had one such situation roughly every two sessions (we always failed those situations), that's definitely something I'll ask him about.

But nonetheless, I feel this is a thin line as no explanation exist about what help is (instructions, physical help, etc.). If more able characters provide instructions, are those help? How is help defined, and when does an individual ability check become a group ability check?

Answer 1

Use group checks when an individual failure would mean the group fails.

First, the rules for group checks:

When a number of individuals are trying to accomplish something as a group, the DM might ask for a group ability check. In such a situation, the characters who are skilled at a particular task help cover those who aren't.

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. Group checks don't come up very often, and they're most useful when all the characters succeed or fail as a group.

It is important to understand the purpose of group checks. Group checks are called for when a single individual failure would normally mean the whole group fails. This is what "succeed or fail as a group" means. This is exactly the situation you described: if we run each character's checks individually, a single failure means that character falls off the cliff. This is a failure for the whole group. When one character falls off the cliff, it derails the entire party. Now the character that fails has to be rescued, the whole party has to descend the cliff, the entire task has been successfully failed by everyone.

Using individual checks when a group check should be used almost guarantees failure.

Using group checks serves to make the laws of probability less punishing. When you have a party of six trying to scale the cliff, individual checks means you have to have six out of six successes, else the whole group fails. Group checks means you only need three out of six successes. Individual checks, when a group check should be used, almost guarantees failure, as you have observed.