There’s a gameplay principle articulated in Burning Wheel called Let It Ride. The idea is that in most situations, when a player scores a success on a test, the player doesn’t need to roll again unless circumstances change. For example, the player’s called to make an Athletics test to climb a cliff in the face of howling winds while exploring the Plateau of Leng; once the character succeeds, the GM shouldn’t keep calling for more Athletics tests.
In general, GUMSHOE’s well suited to letting things ride. Indeed, given the way General Ability pools deplete, it’s much more fun to let success on simple tests persist. This is especially true for the more obscure General Abilities – if only one player has any points in Pilot, let their one Piloting test cover the whole flying-the-plane-through-the-raging-storm.
But…
There’s one place where letting things ride can bump up against GUMSHOE, and that’s covert information gathering, which usually means Stealth tests. In a more combat-focussed game, it’s fine to let the thief’s Stealth success ride for a long while, because all the thief’s doing is gathering intelligence to set up the big set-piece combat that everyone’s waiting for. But in GUMSHOE, the mystery’s the centrepiece of the game, and in some scenarios, a hidden observer can short-circuit everything.
For example, I was running a game where the action centred around intrigue in an inn. In other playtests, the players did as I expected – they went in, questioned the various suspects, gathered clues, speculated about motives and so on. But in the most recent run-through, one high-Stealth character crept in the back door of the inn and spent as long as they could hiding under tables, eavesdropping, rifling through rooms, and generally avoiding interaction with the NPCs while grabbing everything even vaguely clue-shaped.
Now, I could have called for a bunch of Stealth tests, but that’d be an unexpected and even vindictive change of play style. Instead, I took advantage of GUMSHOE’s pool system. I ruled that the player’s successful Stealth test would keep working, but they had to pay a point of Stealth whenever they moved from room to room or grabbed a piece of evidence. This meant the player could still act while hidden and got the advantage of their successful hiding attempt, and could even plan their actions with a measure of confidence – but there was a clear time limit on how much they could safely do.
(If the player didn’t want to or couldn’t spend a point, they could still try rolling.)
It worked well enough that I’ve added to my GUMSHOE toolkit – it’s ideal for times when I want the player to be able to pick from a menu of potential fruits of success, but I don’t want them to take the whole fruit basket. I can see myself using it for stuff like Digital Intrusion in Night’s Black Agents too (you hack the Conspiracy’s server – here’s a list of subsidiary systems to poke at, each one costs you one point of Digital Intrusion to peruse), Bureaucracy in Fall of Delta Green, or Hiding in Fear Itself.
But mainly I’ll use it for annoying stealthy halflings spying on my inn-trigue…