There was an excellent post here, over at The Mule Abides about illusionism in the context of wandering monsters. I had no real reply to it then, except for two things.
A) The post is excellent enough that I added it to my On the OSR Required Reading List post. Seriously, it's that good. Secondly I posted about it in the comments to let Tavis know that I had. This comment was promptly deleted, or perhaps held up by the spam filter. Is it spam? Perhaps it was. My ego will recover from his desire to keep the comments focused on the discussion over the post.
B) I love this quote:
Even though at one level we know that some of these events are the result of random rolls on a chart, at another level we treat the dice as oracles that reveal this other world.I have nothing to add to his post because it's succinct and true.
However Dreams in the Lich House has written a 2 part article, here and here. Illusionism is discussed here and here.
Basically, it's the 'wizard switch' given often as advice to new DM's, i.e. There is a lever. If you pull the lever, it activates the trap, if you don't pull the lever, it doesn't disarm the trap. Either way this trap is going off because I spent an hour making it.
Beedo postulates the all too common occurrence in any sort of Space Structure or Line Structure. He describes an environment where everything is frozen until the PC's arrive. It doesn't matter how long it takes them to reach that certain area of the sandbox, the event is static and triggered on the event of the PC's arrival.
His post is also tangentially talks about ignored plot hooks, and how it's textbook illusionism to just move the encounter over to where the PC's are.
MAIN POINT
I think illusionism is abhorrent in both D&D style games, AND story based, plot arc games.
Zack S made an offhand comment about how he would give his players four options, and if they choose to do a fifth, he would not pallet swap a previous encounter but come up with something new for them to do. I feel this is important, as in a key component to the empowerment of the players, and critical to the enjoyment and long term health of the game.
Players must not just believe that actions have consequences, but they actually must have them, not just the illusion of them.
Beedo writes about dangling plot hooks and the players not reacting to them right away. This is an example of how Time Structure is used. If a person is actively pursuing a goal, then they should achieve realistic progress towards that goal. A person, in this case, referring to the entity at the ignored plot hook.
The initial thing that prompted me to reply, is that I have an actual play example. My last long campaign was a wilderness sandbox set up as a colony on foreign shores. They were given the information that the last colony was destroyed. They spent almost a year of game time, exploring the area, visiting different sites, etc. It was nearly 8 months game time till they visited the site of the previous destroyed colony, and they did no research or showed no interest in tracking down any of the leads discovered within that session.
They were astoundingly bothered by the fact that while they were off exploring some site, the colony was wiped off the map the same way the first had been. This was a natural consequence of their choice to not follow up on a plot thread. The effect it had was powerful, upsetting to many of the players. Someone at some point said something akin to "How could we have done anything to stop this?!" as an argumentation towards it being unfair. Cleric spells, locating a sage, showing the evidence to someone in town, or trying to make contact with the native cultures were presented as options in response. The main issue was, the party didn't make it a priority.
This is better than fine, it's wonderful. What they did make a priority was thoroughly getting a lay of the surrounding land and finding interesting environments to find magic and treasure. They were very successful at this. This is the best type of play because player choice matters. This is identifiable as good play, because of the emotional reactions of the players.
They felt bad, because those city people had been captured by shaugin. The reason they felt bad is because they realized that it was not as a direct result of their choice to do something, but a direct result of their choice to not do something.