"The GM announces that they are making an intrusion and hands the player whose PC is the primary target of that intrusion 2 XP. That player can either spend 1 XP they already have to cancel the intrusion (returning the 2 XP to the GM) or they can accept the intrusion, take 1 XP for themselves, and give 1 XP to another player."Justin Alexander reviewing Numenera's "GM Intrusion" mechanic there. And although he musters a spirited argument for why the rule is less obtrusive than some dissociated mechanics, something like that would sure snip the strings on my willing suspension of disbelief.
Where this kind of mechanic differs from the kind of negotiation with the referee you get in improv moments of role-playing is in the bartering of XPs. And clearly the main effect of that is to remind you it's a game. Poetic faith withers when you start doing a cost-benefit analysis.
What it reminds me of is boardgames. A lot of RPGs these days try very hard to be boardgames. That's not necessarily a criticism (hey, have fun whatever way you like) but I'm curious as to what's driving the trend against immersion. Is it a stab at Brechtian alienation? Is it because RPGs need to impress as reading material rather than playing material so as to get good reviews (ie most reviewers read them like a book, they don't playtest them)? Is it because new RPGs are catering to the players who are embarrassed about staying in character? Is keeping an authorial distance from their characters something that players have picked up from videogames? Are roleplaying designers coming up with narrative mechanics in a bid for respectability? ("Hey, I'm not just inventing rules, I'm shaping an art form *...")
I'm interested because I'm thinking of putting a (sort of) story-guiding element in my Zenotic Dragon Warriors 2e project, sometimes known as Jewelspider. And most of my thinking has been in the direction of making it work without jerking the players out of character. So if you've played a system like that and found it doesn't spoil your immersion, do tell.
*Re that, listen to this episode of Improvised Radio Theatre With Dice where, from 41m15s onwards, Roger Bell West and Michael Cule discuss the aesthetics of roleplaying, and whether adhering to genre breaks what's good and unique about roleplaying by slaving it to fiction. I note that in real life we don't expect to continually perceive the aesthetics of a story form in what we're doing (though sometimes we experience "atomic narrative" elements that we later weave into a story) but instead react in the moment to the aesthetics of beauty (a sunset) or character (humour) or wonder (a new idea or experience).