Short of creating a large, scattershot table of wildly different "unintended effects" and having the player dice off it blindly, I don't know how to game with that sort of randomness. I can't do it as a GM; I can make up stuff on the fly, but it's way too correlated with what I've been doing or thinking about for the last few minutes/hours/days. And, it's inevitably filtered through my own preconceptions about what is appropriate to do to characters in my game.
The problem with really unknowable of that sort is that it gives the GM carte blanche to do whatever s/he wants with the characters whenever s/he wants, and there are GMs out there who can't resist yanking that chain (or pulling those wings off of those flies) in ways that are to my thinking completely inappropriate.
I admit that I am notorious in our group for never allowing my character to be captured. NEVER. Doesn't matter how far along in the campaign, it's suicide when that approaches, and (in HERO terms) I pay the cost of that mechanism at character creation so it is present (if, perhaps, unexplained) from Time Zero. As a player I admit it is irrational and it's there, and it's drawn comment before on these boards in threads that no longer exist. And it's there because one of my earliest extramural RPG experiences was one where capture inevitably led to the functional equivalent of mind control earworm, and the GM relished abusing people (players, not characters) via that channel. And no, that SHOULD NOT BE PART OF THE GOALS OF ANY GM'S GAME. Got something you as a player object to doing in a game, and you express that objection in the session? It'd happen, guaranteed, in the next session or two, if the GM could fabricate a reason to compel the character to do it. No, that's not what an RPG should be about, but at least at the time I encountered such a GM, these made a nontrivial fraction of the RPG community.
(That experience was part of what led me to absent myself from RPGs for most of a decade, but the bigger part of that was that it coincided with most of grad school and the first couple years after it, when I really needed to focus on Other Stuff.)