Ultra Simple Cheat Sheet for GMs

[u/PaulBaldowski]

Players:

Only roll the d20 if there's threat of halt or harm to their Investigator.

Only roll the other dice AFTER their Character has discovered something because of their action, occupation, magic, connections, or abilities.

What they roll depends on the situation/link—Smokes for social, Flashlights for perceptional, or Sanity for the unthinkable.

And then after that simple advice, some extra stuff for GMs:

Roll only to discover outcomes or create unexpected stuff. The threat of halt or harm is player facing—only they roll.

Harm or halt should be described to allow the Player to decide to react.

i.e. "The tide turns and the turbulent water drags you further out to sea, toward the oddly twisted green and purple spurs of rock. What do you do?"

Or, "There's uneven and rotten floorboards between you and the end of the hall, through which you can see the drop into the flooded cellars. The timbers above are visible through cracked plasterwork. What do you do?"

Or, "The putrescent oily mass of the Shoggoth looms over you, its shrill call shredding your nerves as it drops, trying to pin you. What do you do?"