Onscreen and textual body armor is plot armor, metaphorically speaking. If the depiction of the armor doesn’t make sense, the audience’s suspension of disbelief will suffer to a degree due to the Dunning–Kruger effect among those with knowledge of the domain, or that same effect may be canceled out by the so-called rule of cool.

https://en.wikipedia.org/wiki/Plot_armor

https://tvtropes.org/pmwiki/pmwiki.php/Main/PlotArmor

https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

https://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool

The best/worst example of this I can think of is the Christian Bale movie Equilibrium (2002), where Bale’s main character doesn’t even wear armor at all, instead favoring some kind of gi or frog uniform from what I can tell. The gunkata “firearm martial art” conceit hand waves some of that away as its practitioners supposedly being much less likely to be in the line of fire, but it ends up being a bit too much like literal plot armor to be believable.

https://en.wikipedia.org/wiki/Frog_(fastening)

https://en.wikipedia.org/wiki/Mandarin_collar

https://tvtropes.org/pmwiki/pmwiki.php/Film/Equilibrium

https://en.wikipedia.org/wiki/Equilibrium_(film)

> Angus Macfadyen's character, Vice-Counsel DuPont, describes the fictional fighting style gun kata in the film:

>> Through analysis of thousands of recorded gunfights, the Cleric has determined that the geometric distribution of antagonists in any gun battle is a statistically-predictable element. The gun kata treats the gun as a total weapon, each fluid position representing a maximum kill zone, inflicting maximum damage on the maximum number of opponents, while keeping the defender clear of the statistically-traditional trajectories of return fire. By the rote mastery of this art, your firing efficiency will rise by no less than 120 percent. The difference of a 63 percent increased lethal proficiency makes the master of the gun katas an adversary not to be taken lightly.

> Kata (型, かた) is a Japanese word for standard forms of movements and postures in karate, jujutsu, aikido, and many other traditional martial arts. The gun kata shown in Equilibrium is a hybrid of [writer/director Kurt] Wimmer's own style of gun kata (invented in his backyard).

Gun kata is essentially a MacGuffin that takes the form of a fictional fighting technique, likely inspired by survivorship bias, but with little to no apparent basis in reality or actually existing fighting techniques, but that's not what it's for; rather, it films extremely well and sets up some decently well-done worldbuilding alongside some decently believable fighting sequence set pieces.

https://en.wikipedia.org/wiki/MacGuffin

https://tvtropes.org/pmwiki/pmwiki.php/Main/MacGuffin

https://en.wikipedia.org/wiki/Survivorship_bias

https://en.wikipedia.org/wiki/Set_piece

https://en.wikipedia.org/wiki/Gun_fu

> Anthony Leong wrote of the gunfights in A Better Tomorrow,

>> Before 1986, Hong Kong cinema was firmly rooted in two genres: the martial arts film and the comedy. Gunplay was not terribly popular because audiences had considered it boring, compared to fancy kung fu moves or graceful swordplay of wuxia epics. What moviegoers needed was a new way to present gunplay—to show it as a skill that could be honed, integrating the acrobatics and grace of the traditional martial arts. And that's exactly what John Woo did. Using all of the visual techniques available to him (tracking shots, dolly-ins, slo-mo), Woo created beautifully surrealistic action sequences that were a 'guilty pleasure' to watch. There is also intimacy found in the gunplay—typically, his protagonists and antagonists will have a profound understanding of one another and will meet face-to-face, in a tense Mexican standoff where they each point their weapons at one another and trade words.

Tangentially related:

> Why “Cool” Military Gear Never Actually Works [video]

https://news.ycombinator.com/item?id=42285468