iserith
Magic Wordsmith
You are quoting the middle path. This cuts both ways.
The player should also not be able to coast on his own knowledge without occasionally having to roll - always avoiding the dice has drawbacks too.
That's why I said self correcting.
Yes, I am quoting the "middle path," as I invariably do in every thread that gets into DM adjudication as it's the path I follow and the DMG recommends (in that it offers no drawbacks compared to two others). It's just that some people think that the player trying to avoid rolling a fickle d20 by doing what he or she can to remove uncertainty as to the outcome of the task and/or the meaningful consequence for failure - which is the smart play - is somehow the same thing as the DM never calling for checks. It's not. If the player is having his or her character boldly confronting perils as the rules imagine they will, there will be plenty of uncertainty and meaningful consequences for failure that the player may not be able to remove or mitigate. Sometimes, the player is going to have to roll.
In any case, none of this limits what the player can state as an approach to a goal, even the character's stats and abilities. Plunk's low Intelligence only bears on the action declaration to the degree Gary wishes it to. The outcome, however, is up to the DM. The DM can decide that the action is automatically successful or needs a check with advantage. Or the DM can say the task is impossible or needs a check with disadvantage. If the DM wants to encourage Gary to play Plunk as the sort of moron the DM imagines him to be, the DM can offer Inspiration when Gary chooses to do that.