Running Mysteries - Investigative Abilities and Theories

Mysteries have always been my favourite thing to run in RPGs, but have also been a little tricky. The real difficulty with mysteries, for me, is twofold - getting players to find the stuff they need to, and dealing with bad rolls that inconvenience both players and the GM. In Open Legend, every roll matters, so bad rolls aren’t such a big problem. However, if you want to make clues easy to find while still making the collection of clues part of the narrative, I have adapted Gumshoe’s investigative abilities to Open Legend, something that I’ve found has massively improved mystery games.

Investigative Abilities

Characters may have two investigative abilities. They can use these to collect clues in a mystery game. In most cases, the GM will have set these clues out into the environment already. If the player is in the location with the clue and effectively describes how their character uses their investigative ability to search for clues, they may automatically succeed at getting the clue without having to roll for it.

Investigative abilities may not be used for anything but this. Characters with Knowledge or Sworn Enemy can count these as additional investigative abilities (on top of their usual two). For example, a character may have Knowledge (Geodes). They therefore also have Geodes as an investigative ability, and can still pick two more investigative abilities.

Players may make up their own investigative abilities, once they are vetted by the GM. An investigative ability should not be too broad, but should still be general enough to be useful for gathering clues.

Example investigative abilities:

  • Fashion
  • Outdoors
  • Photography
  • Pop Culture
  • Research (ability to look things up)
  • Academia
  • Area Lore
  • Gossip

In addition, a 1-cost feat adapted from Star Trek Adventures’ ‘Working on a Theory’ which helps mysteries and investigation, both in and out of mystery games.


Prerequisites: None

Feat Points: 1

Once per session, you may declare that you are working on a theory, and define the nature of this theory. For the rest of the session, you may gain Advantage 1 on all Mental attribute rolls (Learning, Logic, Perception and Will) that are related to the theory you are pursuing. You may pursue only one theory at a time, but may change your active theory whenever you succeed on a Learning or Logic roll related to a new topic or theory.

There has been some discussion on the Discord that is worth sharing around this. I have tried to model this after Sworn Enemy, also 1 feat point - which, while missing the extra language has the advantage of being guaranteed to be useful every session.

However, some GMs have said that they would give these advantages anyway, or would use it as a setting rule. Others have said that having it a feat is too high a cost, and suggest making it a perk instead. So, if you feel the same way, just remember that it doesn’t have to be a 1 cost feat!


While I’ve nothing to add on how Theorist should be granted, it and the Investigative Abilities seem very good, and I like Knowledge and Sworn counting as bonus Investigative Abilities, too.

Personally, your examples make me want to make a campaign just to have an excuse for the “Pop Culture” ability to be of some use.

So first of all, when running mysteries I found this advice very helpful:

For any conclusion you want the PCs to make, include at least three clues.
Why three? Because the PCs will probably miss the first; ignore the second; and misinterpret the third before making some incredible leap of logic that gets them where you wanted them to go all along.

It’s taken from the following article:

Now lets get to your feat, which I have two minor problems with:

  • At the beginning of a mystery or an investigation the players won’t or shouldn’t know too much, so they probably won’t benefit too much from the feat

  • I wouldn’t include Will in the advantages granted, because granting advantage to 4 different attributes seems too potent to me and Will doesn’t even fit that well with investigations. Even 1 feat point for 3 attributes seems still very strong, so I would consider raising the cost to 2

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