Stormtrooper effect

The "or otherwise supposed to" refers to robots, otherworldly beings with notable fame on the subject matter, and so forth.

Generally speaking, this raises questions on how they managed to do the things they're claimed to have done if their skill level is the one you see.

Note that although this, and the TV Tropes equivalent, is named after Stormtroopers from Star Wars, the effect was well known long before any Star Wars movies or novels were published. Usually seen that the bad guys couldn't hit any of the protagonists unless the plot called for drama (thus never lethal even).