In Avengers: Infinity War, Black Widow uses taser on Thanos. Maybe, she didn't know that Thanos was more powerful than the Hulk, but she definitely knew about the Infinity Stones.
What made her think that a taser would work on Thanos?
Science Fiction & Fantasy Stack Exchange is a question and answer site for science fiction and fantasy enthusiasts. It only takes a minute to sign up.Sign up to join this community
I think you have to ask yourself what the alternative is. Basically all of the Avengers (and their new buddies) try to get him with what they got. Loki tried to stab him with a knife, Gamora tried to stab him with a knife, Nebula tried to stab him with a sword, Banner tried to punch him, Black Panther tried to claw him, Falcon tried to shoot him with pistols, War Machine tried hitting him with rockets and bullets, Okoye threw a Wakandan spear, Bucky shot at him with a powerful rifle, Groot tried to cover him in vines and Cap'n America's master plan was to punch him a few times. With that in mind, how is using a high-tech taser any less of a good/bad idea than any of the above?
The other option would have been for her to spend time looking around for gun (bad idea, she might not find one) or try kicking him several times (bad idea, he's very strong). Neither of which is an especially good idea. And heck, the taser might have worked. How stupid would it have been not to at least try it?
You might also want to note that in the prior films, her electricity-based weapons have always proven consistently effective against aliens and other baddies.