Technological disparity

Contrast: (unlikely to occur with this)
* Fragile protagonist
* Realistic damage

People picking up swords and other melee weapons (including lightsabers and such) into gunfights and they can hold their own in such is a blatant example.

Notes:
* This is a clear departure from realism in most cases. However, for example, Japanese used katanas in WW2 much like other nations used bayonets.
* For melee weapons (knives) and such used by stealth operatives this can be ignored if they're only used for killing people stealthily and not for open confrontations.
* Common in Chinese, Japanese and such fiction?