It's of course a basic expectation that any actor arrives to set fully prepared, with their lines for the day memorised and their game-face on.
Yet how much effort an actor is expected to put into a scene scales to the length and perceived "importance" of that scene, such that where most cameo appearances are concerned, there's generally a lot more winging-it involved.
But not with these 10 tiny roles in films, which saw actors put in wildly over-the-odds commitment to their parts, spending weeks or even many, many months getting into character and honing their craft.
And yet, most of these actors were actually on set for mere days, and even if not, their screen time ultimately only amounted to a few scant minutes peppered throughout the movie.
As such, there's a gigantic chasm between the commendable amount of blood, sweat, and tears the performers put into these roles and their visibility in the movie as a whole.
Perhaps they simply relished the challenge that the part offered, but on the other side of the coin, some of these actors were clearly expecting to appear a little more prominently in these films...
10. Johnny Depp - Platoon
Johnny Depp appears periodically throughout Oliver Stone's classic war film Platoon as soldier Gator Lerner - a background character who doesn't get much to do, yet for a 22-year-old Depp, it marked one of his first major screen credits.
And in addition to being put through a month-long military boot camp alongside his more famous co-stars, Depp spent months prior to shooting learning Vietnamese.
With his character being an interpreter who speaks Vietnamese throughout the movie, Depp wanted to ensure he nailed the part and not merely do the most superficial bare minimum to convince.
It's also worth noting that Depp originally had a larger role in Platoon which would've made greater use of his studying, yet several of Depp's most prominent scenes ended up being cut by Stone, ensuring that he put all that time into learning the language for mere scraps of screen time.