Have you ever played a game like Scotland Yard? This is a board game in which the players cooperate against a secret keeper who plays the villainous Mr. X who is trying to escape the players chasing him. The game plays out on a stylized map of London with cabs, buses, and trains that each character can take to travel from one point to the next each turn. Each player has a certain amount of resources and Mr. X disappears stealthily as the players chase him, turning up only at predefined moments, while trying to stay a step or two ahead of his pursuers. It's great game. And it has well, lots of prep.
Nope, sorry, don't know that one.
Imagine trying to run a similar game as the secret keeper without prep. You have no map. Each turn you are drawing new connections on the map. The players have no idea where each connection is going to go. They can't plan ahead. You have to decide at each step what connections exist for both Mr. X and the players to take. You also have to decide when Mr. X will appear. Who would possibly think that your ad hoc game provided more agency for the players than the prepared one? Who would possibly imagine that game balanced? Why would anyone think the outcome of the chase was decided by anything but your fiat?
Anyone who understands how mechanics in a TTRPG can be used to decide the outcome of things...
In an RPG, the situations in a prepped game is even more constrained. In "Scotland Yard" one of the things that balances Mr. X with those chasing him is Mr. X has unlimited in game resources - that is he always has the train ticket or bus face he needs. But in any reasonably RPG scenario the escaping criminal has only limited resources - minions, transportation, hit points, spell slots, bullets, whatever. For example, in a prepared game, you could write, "Four blocks from the antiquities store, Mr. X has stashed a small motorcycle, which he intends to use as a getaway vehicle on the crowded streets." If you are improvising, you have to decide when Mr. X can find his motorcycle, or you might not think of the possibility of a motorcycle until you are some ways into the chase. Depending on the game system the writers might even encourage to invent a motorcycle on the spot in response to a die roll by the players or to heighten the dramatic tension. And yes, that creates a certain sort of game that could be fun, but you can't claim that the Schrodinger's Motorcycle that isn't anywhere until you place it gives more agency to the players to stop Mr. X than a game where the motorcycle exists in a certain place.
Well, unless you tell the players beforehand about the bike, it effectively doesn't exist, because they have no idea it exists unless you tell them! If you tell them about the bike, whether you created it beforehand, or improvised it a moment before, then, and only then, does the bike actually exist.
Or imagine something more immediate. The PC's spot the villain on his motorcycle and give chase. Imagine the difference between having prepared the city street with its traffic and the events and improvising them on the fly. This turns out to be exactly like the scenario of trying to play the game 'Scotland Yard' without prep, just with a different sort of map. What obstacles you place in the way of each character are now up to you to decide at each moment. Whether the semi crosses and when and whether the fruit seller comes out in front of the players with his cart and so forth is all something you have to think about on the fly. It's strikes me as impossible to improvise this with the same level of detail as you would if you had prepped.
I'm sorry that your imagination is limited that way.
I can think of a certain Dungeon magazine adventure where the PC's are chasing a criminal through the docks and there is a chase that occurs by jumping from the deck of one boat to the next. I think it would be impossible to improvise that scene on the fly and be as fair or as interesting or give the players as much agency as if you put the map down on the table and said, "You are here and here is Mr. X how do you want to get to him?" Especially when if you didn't have prep you'd be improvising at each step where the complications would occur, like which boats have hidden obstacles and what those obstacles are and so forth. The idea that I have this prep limits the players ability to make meaningful choices more than a situation where I have nothing prepared just doesn't work once you remove it from the realm of nebulous theory crafting and actually start talking about real situations that come up.
Uh...okay...
You said you resolve a chase using the applicable game rules and randomizers. That tells me you don't really run chases. You've never had the PC's galloping behind a carriage being attacked by wights down a twisting mountain road, trying to intervene before the carriage doors are ripped off, or the roof is bashed through, or once the driver is killed the carriage careens off a cliff or out into the stony woods and the baron and baroness are killed. Because if you ran those sorts of scenes frequently, you'd know that a) most games don't really have a lot of good rules for them and b) a lot of the outcome depends less on the rules than on the map. Imagine how much you have to decide at that point that constitutes the map of the scene. All the different characters, hit points and hardness of the carriage, the map of the mountain road, the monsters, etc. More prep in that scene doesn't give the players less agency. What it does is take away some of your own agency. You have to commit to something.
Well, just because you personally don't like a particular ruleset doesn't invalidate the ability to use it to decide the outcome of a situation. As for the stats of things and NPCs and stuff, either the game already has those, in which case I use them, or I create something on the fly at the beginning of the chase.
The biggest myth you are pushing is that nothing set in stone means unlimited opportunities. If nothing is set in stone there are zero meaningful choices. You are in cloud cookoo land. Anything can happen. Only after things start happening does the player have some meaningful choices, but even then it's like trying to play Scotland Yard without a board or with a board that changes according to the secret keeper's fiat.
Well, unless things that require the players to make choices are actually happening, how would they even know they need to make a choice. You seem to be under the impression that players can somehow have knowledge about what you have prepped without you telling them about it, which is simply not true. Until information is provided to the players that frame potential decision points, the players have no clue. Only when the decision point has been framed, and the players are informed of the need for them to make a decision, can a meaningful choice be made. Whether or not the decision point has been prepped beforehand, or improvised a moment before, is effectively irrelevant.
Besides which, to be frank, no improv GM I've ever encountered is actually creative enough to do any of this.
Well, just because you haven't met them doesn't mean they don't exist. I've met them, and I have a fair amount of anecdotal reasons to believe I am one.
Improvisation almost invariably ends up involving no map and no real travel.
Well, my games take place in some sort of setting. I admit that I am lazy and usually use published settings or the setting attached to a particular game. Either way, they come with a map of sorts. At the least, some sort of "setting" will be decided during session zero based on the premise of the campaign. The details of the setting can be improvised on the fly, as until the moment a player asks about details of a certain aspect of the setting, they don't matter. Like I said before, until the players actually interact with something, it effectively doesn't exist, whether or not it's written down in the GM's notes. Once the aspect of the setting is interacted with, then, and only then, does it become an existent thing.
The style is less sand box with a map to explore than it is a Shakespearian stage the players are on where the drapes and props come and go when the scene shifts. You can go anywhere but everywhere is basically the same, just new characters come onto or exit the stage. Exit stage left, arrive stage right. And to the extent that anything is dense, it's probably someone else's prep that they are bringing into the situation to make up for the lack of their own.
Or, until the details of something are needed, they don't matter. Like I said before, for me anyway, improvising new content is super easy. I don't need to sit around contemplating things to add detail to the narrative, I just decide something and run with it. Everywhere is, in one way, exactly the same, in that it effectively doesn't have any detail, until the players decide they want detail, or they choose to interact with it. Once those details become required, said detail is added to the setting by improvising said detail on the spot. Once added, the details become an existent thing, and are manipulated as needed afterwards.
Don't worry, I've met a lot of prepper GMs that have trouble understanding the idea that things only begin to exist within the narrative once the players are actually aware of them. You can have a huge castle with an intricate map fully detailed in your notes, but unless the players are told about the castle, it may as well not exist. I will admit though, that you are correct about the aspect of someone elses prep making my job as an ad lib GM way way easier, because I do use settings, maps, stat blocks, and other similar things in my games. Honestly, I could improvise all that stuff if I needed too, but why bother when I have a plethora of things available already.
