While gathering core clues and making General ability tests are fairly easy to grasp, many beginning GUMSHOE players and GMs have trouble coming up with ways to make Investigative ability spends useful. Here's a list of benefits you might get from spending an Investigative ability point.
- You earn additional information that lends context to a core clue but is not strictly necessary to progress. (In essence, you make the mystery "easier" by putting the different pieces together faster.)
- You gain a useful resource related to your area of expertise. The GM may still call for a Preparedness test for a particularly rare resource; this spend gives a +3 bonus to that test.
- You change the attitude of an NPC, making them more helpful to you and your allies or turning them against another character.
- You gain information that reinforces your skills or restores your confidence in them. Refresh a General ability pool by 2-3 points.
- Rather than tying into your own abilities, the information opens up new avenues or gives you some other kind of edge. Create a pool of 2-3 temporary ability points that function as either an Investigative or a General ability you may not otherwise possess.
- You learn a technique that makes a task easier or find a loophole or weakness you can exploit. Lower the difficulty of tests of a certain kind by 1 for the rest of the scene. (In the case of combat abilities, this may instead lower enemies' Hit Threshold by 1.)
- You create a condition that hampers your enemies. Subtract 2-3 points in one pool from each of the affected opponents. (This will usually apply to combat abilities or Health.)
In some cases, the advantage offered by an Investigative spend may still require a General ability test to secure. In these cases, the GM may increase the benefit based on the difficulty of the test or the amount you roll over that difficulty. This is especially true if the benefit applies to the entire party or hampers many opponents.