“The players have ruined my adventure!”
I see a lot of GMs say this. It generally means that their players have done something that they didn’t expect. And now what are you supposed to do?!
Well, unless it’s a convention game (or some similar situation where there is a strictly limited amount of time available), my answer is invariably going to be, “Let’s see what happens.” (While doing a little happy dance in the back of my brain, because this is what makes RPGs so cool.)
In practical terms, it’s very easy for my players to do something which I hadn’t anticipated. But it’s generally very difficult for them to do something that I have absolutely nothing prepared for. I just don’t prep my scenarios that way. It’s more typical for them to do something unexpected and now the guy that I thought was going to be their patron is, in fact, their arch-enemy. But I still had the guy prepped, right?
So when the PCs have done something radically unexpected, most of the time I just keep doing what I was doing before: Selecting the tools built into the scenario and actively playing them.
In some cases, the PCs will end up tumbling into a section of the scenario that was prepped for a completely different type of interaction. (Common variations include “I didn’t think I’d need a stat block for that character” in relatively complex systems where stat blocks are time-consuming or “this will involve several dozen pieces moving in directions I didn’t anticipate”.) If this happens, I’ll generally call for a 5 or 10 minute break so that I can juggle the pieces into place smoothly.
For example: In my regular D&D campaign a long while ago, there was a situation where some allies of the PCs were going to get involved in a street war. But based on what the PCs were planning to do, it was pretty clear that they weren’t going to be directly involved in the street war. So I prepped that as a sequence of events that the PCs would hear about afterwards. Then the PCs shifted direction and ended up unintentionally right in the middle of the street war: So I took a 10 minute break to prep the additional stat blocks I needed.
In extremely rare cases, the PCs will manage to perform a complete scenario exit. When that happens, I will generally bring the current session to a close and spend the time necessary to prep the new scenario. (Generally you want to ad lib along the new path for a certain distance until the new frame is both clear and the PCs have clearly committed to it. If you imagine that the campaign is currently in Houston and the PCs decide to go to Dallas, you can probably get a fair distance down the freeway or all the way to the city limits of Dallas as you wind things down for the night. This is partly because it will help focus your prep for the new scenario. And it’s also because the players will sometimes abruptly reverse course and drive back to Houston.)
One example in my D&D campaign occurred when a PC landed on top of a randomly generated NPC after a failed teleport attempt. They became almost immediate friends and it turned out that the randomly generated NPC was on his way to a dungeon that he’d discovered. The PCs decided to tag along… to the dungeon that I had literally just created 5 seconds earlier. We were close to quitting time for the night in any case, so I wrapped things up and prepped the dungeon.
(The PCs then promptly decided not to go to the dungeon after all at the beginning of the next session and I had to scrap the entire dungeon. Which is the most prep I’ve had to scrap in the last 7 years of GMing.)
A more recent example occurred when I was running Eternal Lies: The PCs decided to aggressively pursue a two word reference in a letter that I hadn’t anticipated them glomming onto. In that case, we had enough time left in the current session that they booked their flights and, quite literally, got to the city limits before we broke for the night and I prepped a whole new scenario for them.
I can’t imagine having to ‘prep’ a dungeon. Even in the good old days there were PLENTY in magazines and well Dungeon magazine (and Pegasus, White Dwarf, etc.) Now on the internet there are literally thousands of dungeons and one-page dungeons that I think it would be easy to have a couple in your back pocket. You might want to read and tune them, but I’d think having some placeholders would always be a good idea!
If you have a fairly unique setting, then you’ll need to prep a bit in preference to off-the-shelf solutions. You don’t want to toss in a goblin hoard in a world w/o goblins, for example. That said, I do like to collect little pocket settings–eg, five room dungeons–you can throw down for players who bedevil your plans.
I’ve found it’s good to have some pre-gen combatants ready for the encounter that goes aggressive. Other than that, most other NPCs you can wing. And I also do favor those systems that are simple enough to allow you to wing it, in the sense “this character is competent, this character is a master.” I don’t know that I’d run a sandbox w/o that assurance.
I like your adventure design philosophy and it’s one that we push: don’t over prepare. Don’t write the adventure that your players on keen on taking. Even when you prep material- there’s ways of getting your players there while making it look like it was their choice.
The instance of your players deciding not to follow the NPC into the dungeon, even that could have been alleviated by checking-in with the players to see what they wanted to do. The only way I’ve “lost as a GM” was by writing the story regardless of the actions that my players actually wanted to take- heck so much information can be gained by just asking your players their plans for their characters.
“… even that could have been alleviated by checking-in with the players to see what they wanted to do. ”
Not really. The last thing they said in the session was, “Let’s go to the dungeon!” They didn’t change their minds until about 20 minutes into the next session.
While I’m a huge advocate of the idea that, “What are you planning to do next session?” is a huge tool in the GM’s arsenal when it comes to planning and prioritizing prep, the reality is that you can’t eliminate every curve ball without eliminating player choice.