Go to Part 1

The PCs are playing agents in the Las Vegas branch of CTU. This mini-scenario begins when they receive an inter-agency intelligence report that a monitoring program established on a known terrorist operation’s bank account information has recorded payments being made on a storage unit in Las Vegas. The PCs have been authorized to execute a search warrant on the storage unit.

The scenario starts at the North Las Vegas Self-Storage on Lake Mead Boulevard (the BLUE NODE).

The storage space itself is stacked high with empty cardboard boxes. Anyone walking past the storage space when the door was open would see a bunch of boxes labeled “LIVING ROOM”, “DISHES”, and the like – but it’s all just for a show. There’s a large gap towards the back where several boxes have recently been removed: Something was being stored here and now it’s gone.

CLUE 1: Checking the rental records reveals that Yassif Mansoor signed the lease on the storage space. The address given on the lease agreement is a fake, but a routine database search turns up a Yassif Mansoor living in the Broadstone Indigo apartment complex on Azure Avenue (NODE A).

CLUE 2: The storage space contains a bellboy uniform belonging to the Bellagio hotel and casino (NODE B).

CLUE 3: There is also a disposable cell phone in the storage space. Checking the call log reveals several calls being placed to a number that can be traced to Officer Frank Nasser (NODE C).

ANCILLARY CLUE: Two detonation caps can be found behind the metal track of the storage space door. (They rolled back there and were lost.)

NODE A: YASSIF MANSOOR’S APARTMENT

Yassif Mansoor isn’t at his apartment, but there are eight terrorists hanging out. Four of them play cards in the living room; two are watching TV in one of the bedrooms; and two more are on the balcony smoking.

CLUE 1: A large metal trash can in the storage closet off the balcony contains the charcoaled remnants of a massive amount of documentary evidence (Mansoor was covering his tracks). Sifting through the ashes reveals a few partially preserved scraps of paper, including part of a Radio Shack shipping manifest including an order number. Tracking the order reveals several pieces of electronic equipment that could be useful in building bombs. More importantly, it also gives them a credit card number and one of the fake names Mansoor was using. If they track recent activity on the credit card, they’ll find that it was used to rent a room at the Bellagio (NODE B).

CLUE 2: If the PCs can get one of the terrorists to crack under questioning, they can tell them that Yassif Mansoor was at the apartment yesterday with a cop named Nasser (NODE C).

ANCILLARY CLUE: There are six suicide-bomb vests stored in the walk-in closet. After the big bomb went off at the Bellagio, these suicide bombers were going to deliver a second wave of terror throughout Vegas. (These bombers, however, do not know the actual target of the big bomb. That information was sequestered.)

NODE B: THE BELLAGIO

If the PCs tracked Mansoor’s credit card activity, then they know exactly which suite he’s rented at the Bellagio. If they only know that something might be happening at the Bellagio then the room can be tracked down in a number of ways: Bomb-sniffing dogs; questioning the staff; surveillance; room-by-room canvassing; reviewing security tapes; and so forth.

Mansoor and six nervous, heavily armed terrorists are waiting in the suite with the Big Bomb (which they snuck into the room on luggage trolleys using bellboy uniforms).

CLUE 1: Yassif Mansoor probably won’t break under questioning, but merely identifying him should allow the PCs to track down his home address (NODE A).

CLUE 2: Sewn into the lining of Mansoor’s jacket is a small packet of microfilm. These contain records indicating that Frank Nasser of the Las Vegas police department is guilty of embezzling from a fund used for undercover drug buys. Mansoor was using these records to blackmail Nasser. (NODE C)

NODE C: FRANK NASSER

Having been blackmailed by Mansoor, Nasser has been helping the terrorist in a number of different ways. (The C4 for the suicide bombers, for example, was taken from a police lock-up Nasser was responsible for. And Nasser intimidated a beat cop into dropping a speeding ticket issued on one of Mansoor’s men.)

CLUE 1: Nasser is more likely to crack under questioning than Mansoor (particularly if the PCs reveal that they have hard evidence of any of his wrong-doing). But he’s also aware of the consequences: If he can, he’ll try to cut a deal before answering their questions.

CLUE 2: Nasser can also be placed under surveillance. He will check in at both the Bellagio and Mansoor’s apartment before the bombings occur.

Go to Part 5: Plot vs. Node

Go to Part 1

The Three Clue Rule states:

For any conclusion you want the PCs to make, include at least three clues.

The underlying theory behind the rule is that having three distinct options provides sufficient redundancy to create a robust scenario: Even if the PCs miss the first clue and misinterpret the second, the third clue provides a final safety net to keep the scenario on track.

This logic, however, also leads us to the inversion of the Three Clue Rule:

If the PCs have access to ANY three clues, they will reach at least ONE conclusion.

In other words, if you need the PCs to reach three conclusions (A, B, and C) and the PCs have access to three clues (each of which would theoretically allow them to reach one of those conclusions) then it is very likely that they will, in fact, reach at least one of those conclusions.

And understanding this inversion of the Three Clue Rule allows us to embrace the full flexibility of node-based design. Here’s a simple example:

The scenario starts in the blue node, which contains three clues – one pointing to node A, one to node B, and one to node C. Following the inverse of the Three Clue Rule, we therefore know that the PCs will be able to conclude that they need to go to at least one of these nodes.

Let’s assume they go to node A. Node A contains two additional clues – one pointing to node B and the other pointing to node C.

At this point the PCs have had access to 5 different clues. One of these has successfully led them to node A and can now be discarded. But this leaves them with four clues (two pointing to node B and two pointing to node C), and the inverse of the Three Clue Rule once again shows us that they have more than enough information to proceed on.

Let’s assume they now go to node C. Here they find clues to nodes A and B. They now have access to a total of seven clues. Four of these clues now point to nodes they have already visited, but that still leaves them with three clues pointing to node B. The Three Clue Rule itself shows that they now have access to enough information to finish the scenario.

(Note that we’re only talking about clue access here. That doesn’t mean that they’re guaranteed to find or correctly interpret every single clue. In fact, we’re assuming that they don’t.)

Now, compare this node-based design to a comparable plotted approach:

Note that the plotted approach can also be broken down into distinct nodes. And in terms of preparation, the plotted approach requires the exact same resources: Four nodes and nine clues. But the non-plotted design is richer, more flexible, and leaves the PCs in the driver’s seat. In other words, even in the simplest examples, node-based design allows you to get more mileage out of the same amount of work.

Of course, this entire discussion has been rather dry and technical. So let’s put some flesh on these bones.

Go to Part 1

Of course, it’s all well and good to say, “Prep Situations.” But one of the reasons people prefer the plotted approach is that it provides a meaningful structure: It tells you where you’re going and it gives you a way to get there.

Without that kind of structure, it’s really easy for a gaming session to derail. It’s certainly not impossible to simply turn the PCs loose, roll with the punches, and end up somewhere interesting. Similarly, it’s quite possible to jump in a car, drive aimlessly for a few hours, and have a really exciting time of it.

But it’s often useful to have a map of the territory.

This line of thought, however, often leads to a false dilemma. The logic goes something like this:

(1) I want my players to have meaningful choice.
(2) I need to have a structure for my adventure.
(3) Therefore, I need to prepare for each choice the players might make.

And the result is an exponentially expanding adventure path:

The problem with this design should be self-evident: You’re preparing 5 times as much material to supply the same amount of playing time. And most of the material you’re preparing will never be seen by the players.

In some ways, of course, this is an extreme example. You could simplify your task by collapsing some of these forks into each other:

But even here you’re designing eight steps worth of material in order to provide three steps of actual play. You’re still specifically designing material that you know will never be used.

And in other ways it’s actually not that extreme at all: The original example assumes that there are only two potential choices at any given point on the path. In reality, it’s quite possible for there to be three or four or even more – and each additional choice adds a whole new series of contingencies that you need to account for.

Ultimately, this sort of “Choose Your Own Adventure” prep is a dead end: No matter how much you try to predict ahead of time, your players will still find options you never considered — forcing you back into the position of artificially constraining their choices to keep your prep intact and leaving you with the exact same problem you were trying to solve in the first place. And even if that wasn’t true, you’re still burdening yourself with an overwrought preparation process filled with unnecessary work.

The solution to this problem is node-based scenario design. And the root of that solution lies in the inversion of the Three Clue Rule.

Go to Part 3: Inverting the Three Clue Rule

Most published adventures are designed around a structure that looks like this:

You start at the beginning (Blue), proceed through a series of linear scenes (Yellow), and eventually reach the end (Red).

Occasionally you may see someone get fancy and throw a pseudo-option into things:

But you’re still looking at an essentially linear path. Although the exact form of this linear path may vary depending on the adventure in question, ultimately this form of design is the plotted approach: A happens, then B happens, and then C happens.

The primary advantage of the plotted approach is its simplicity. It’s both easy to understand and easy to control. On the one hand, when you’re preparing the adventure it’s like putting together a scheduled to-do list or laying out the plot for a short story. While you’re running the adventure, on the other hand, you always know exactly where you are and exactly where you’re supposed to be going.

But the plotted approach has two major flaws:

First, it lacks flexibility. Every arrow on the plotted flow-chart is a chokepoint: If the players don’t follow that arrow (because they don’t want to or because they don’t realize they’re supposed to), then the adventure is going to grind to a painful halt.

The risk of this painful train wreck (or the necessity of railroading your players) can be mitigated by means of the Three Clue Rule. But when the Three Clue Rule is applied in a plotted structure, you run the risk of over-kill: Every yellow dot will contain three clues all pointing towards the next dot. If the players miss or misinterpret a couple of the clues, that’s fine. But if they find all of the clues in a smaller scene, they may feel as if you’re trying to spoon-feed them. (Which, ironically, may cause them to rebel against your best laid plans.)

Second, because it lacks flexibility, the plotted approach is inimical to meaningful player choice. In order for the plotted adventure to work, the PCs must follow the arrows. Choices which don’t follow the arrows will break the game.

This is why I say Don’t Prep Plots, Prep Situations.