metachirality

Yeah, I think that atium/electrum technically show multiple paths, it's just that in a short timeframe it'll be deterministic enough to look like one. I'm not sure if the Vin vs. Zane fight was more probabilistic than deterministic. It seems like maybe it was deterministic but the atium was unable to predict the future because the future depended on what it showed (wouldn't this imply that the shadows should split in the second scenario in the initial post though?). Maybe an Allomantic atium user far away and unable to affect the fight would actually be able to see one single path because the outcome isn't conditioned on what they see. If it was probabilistic, that raises the question of how it's injecting the indeterminism into the Allomancers' actions, because they aren't seeing a random path, they're seeing a single image of all possible paths. The most reasonable explanation I could come up with is that atium also splits the brain activity/processing/cognition for each path and chooses one at random.

Ok, here's a scenario, similar in form to the scenario in the initial post: Let's say you have a safe locked behind a passcode. You commit to doing something different from what your electrum shadow shows unless it shows you inputting the correct code and opening the safe. There are three possibilities for what could happen: (1) You see one possibility where you open the safe. This one is disproven by WoB. (2) You see multiple possibilities, all of which have you opening the safe. (3) You see multiple possibilities, including ones in which you don't open the safe. If this is how allomantic electrum works, it wouldn't be any easier to open the safe compared to just brute forcing it. I think it's probably (3). To see why I think this, you can analogize atium/electrum shadows to time travel. (1) would be like time travel where you can't change the past and everything is predetermined. (3) would be something like Primer, where things play out the same when you travel back in time unless you intervene. I don't know what (2) would be. A fight between an allomancer burning atium and someone who isn't would be like receiving a message from the future telling you what your opponent did, which would allow you to account for and circumvent it. A fight between two allomancers burning atium would be like a battle between two time travelers constantly trying to account for and circumvent the other's actions, which would generate many many timelines. In the locked safe scenario, it would be like receiving a message from the future that you tried a passcode and whether it did or didn't work which would generate a thousand timelines, in only one of which you actually open the safe. In the second scenario from the initial post, it would be like you getting a message from the future describing what you would've done. Since each timeline is slightly different from the last, it would accumulate and eventually you'd reach a timeline in which you didn't receive anything or decided to take back your commitment and that would be about what you would see your electrum shadow doing. I think (3) has the advantage of more easily describing why atium shadows split compared to (1) or (2), in which splitting seems more like an extra case that has to be manually accounted for. Analogizing with time travel once again, this is because if you have consistent timelines, it's physically impossible to not do something you saw you did.

I'm actually starting to think it might just split the shadows. Like if you think of atium shadows as splitting because the future sight can't choose between the different paths, I think something similar would happen with electrum, except this time it's because all paths are possible, rather than impossible. Also if this is how allomantic electrum works, I feel like if you tried to use electrum to avoid dying, like in the scenario I described in my initial post, instead of the shadows splitting instantly you would see a single path where you don't die, which doesn't seem true. Actually, the WoB suggests that, even though it doesn't single out one path like atium does, you can still see the individual paths which is still pretty useful.

In the books, it's stated that Allomantic electrum is pretty useless besides making atium useless. I don't remember if they stated why it was useless but I think I figured out why. Let's say you're an Allomancer in a fight and you burn electrum. You would think that you would be able to see futures where you die and avoid them, but since those would no longer be your futures, the shadows would split instead, much like two Allomancers burning atium in a fight. Here's a more interesting question: What would happen if an Allomancer committed to taking whatever path, if any, the electrum shadow showed as accurately as possible before burning electrum?