Basic Expert
Explorer
Presumably, in the situation of a Strength check to open a door, the consequences of the individual forcing the first check is that the party then must decide to invest additional time and effort (collectively) to try to force it open with a group roll.
Each party member taking part in the door opening exercise wouldn't be able to keep watch for danger, search for treasure, cast spells or take any other sort of action. Whether or not that has an impact on gameplay is largely scenario dependent.
I generally don't like to gate access behind skill checks as that makes progress too arbitrary in my opinion. If I want to block access to an area I make it hidden or allow the party to discover and take specific actions to gain entry (find the key, find the magic word, etc.). However, I will use a skill roll to block access for nonessential side content or if the party is up to some shenanigans in a city and are trying to break into a shop or something.
Regardless of the framing of the use case, the presented system of folding an individual check into a group check remains a valid tool.
Each party member taking part in the door opening exercise wouldn't be able to keep watch for danger, search for treasure, cast spells or take any other sort of action. Whether or not that has an impact on gameplay is largely scenario dependent.
I generally don't like to gate access behind skill checks as that makes progress too arbitrary in my opinion. If I want to block access to an area I make it hidden or allow the party to discover and take specific actions to gain entry (find the key, find the magic word, etc.). However, I will use a skill roll to block access for nonessential side content or if the party is up to some shenanigans in a city and are trying to break into a shop or something.
Regardless of the framing of the use case, the presented system of folding an individual check into a group check remains a valid tool.


