On Tuesday we took a look at the five man crew, and I listed a few ways that it could be viewed as superior to other numbered crews. Even if Hollywood wants to show that 10+ person crews can work just fine (Ocean's 11, 12, 13), which can happen, generally for most large criminal operations you are starting to get a bit too bulky once you cross the magical number of 5. Today, let's look at how we can use the idea of the five man crew for your game.
The PC Crew
This is fairly obvious, but take a moment to think about it. The ideal crew size is 4-6 people, generally 5. The general size for an RPG is 4-6 players, again, generally 5. This is quite a wonderful coincidence and means that, at least for one shots, you can do a very good job of a heist game with your standard party crew. The same logic also applies in forming the crews. Five people lets you balance the roles needing to be done, with the compact and easily organized size that five gets you.
Now, the fun part about doing a PC heist game, or session, is how much of the planning the PCs have to do, and how much of that is in character. This can really cut down on your planning time for a one shot, because - as the GM - all you need to do is give them the mission. "You're being employed to knock over the First National Bank on Bauer Street. Go" The PCs then take over with checking security, stalking guards, checking into personelle, timing police response, etc, etc. John Wick in his game Wilderness of Mirrors even has a way for the PCs to plan the whole thing out for you, getting some mechanical benefit for doing so, and leaving you free to just handle the execution of it.
How is that for a low-plan session?
The NPC Rival Crew
The other obvious way is to make a crew of NPCs who compete with the PCs at every turn. If the PCs go to explore the Caves of Shalamazoon, then you can bet these NPCs will be there also exploring. Do the PCs go to excavate the long lost City of the Dead? Well, guess who found the only other survivor of a trip to that cursed place? (Really, someone needs to make a Mummy RPG...if they haven't already)
Now, the best way to do this is to try and have the NPCs compete, but not necessarily directly oppose the PCs. This minimizes violent conflict (because really, once guns come out the PCs will just kill them all) while letting you bring a real sense of competition into the game. Done right, you can even add more drama to the game by making the PCs rush where they'd normally be slow so they can beat their rival.
Give it a try sometime. I know I'm going to. (It worked great last time I tried, but that was years ago)
Find The Bad Guys
The last way is to just use a 5 person crew as a 5 person crew. They break the law, or otherwise take something that the PCs have to get back. Now the PCs have to deal with an experienced and capable team that know how to work together. The synergy for how a well oiled team can work together is even easier to present quickly, since you - the GM - are controlling all five of them. Meaning you can just do the tricks that the PCs will have to learn how to manage on their own.
This can also be fun, but if you're not careful can also lead to a party wipe. After all, team work can make a group much greater than the sum of their parts, and you don't get much better team work than when one person is controlling everyone, with full access to their skills and abilities.