Whether the characters are fighting men or monsters, they will often attack long after any sensible foe would have attempted surrender or retreat. They may suffer from crippling injuries, or even injuries that will be fatal without treatment.
May be justified (among humans) by having their pride hurt or honor involved, having lost so much that only victory can redeem them, having nowhere to run to, or having an absolutely crucial need for victory, so that flight would just be prolonging their pain, or (among monsters) by having them maddened in some way, but often enough it's just shown. Or maybe the character is simply a Fearless Fool.
Harder to justify, but popular, is that they fight until they drop dead. No one is crippled or disabled by wounds—and not because they took Bottled Heroic Resolve. This can overlap with Critical Existence Failure, especially in videogames.
The Determinator is prone to it, although depending on what he is determined on, he may not engage in it.
Common among Mooks (and many a Glass Cannon), though not the most common form of Mook Chivalry. One sign of The Berserker, who will often continue to attack after all his foes are down, not being able to distinguish between Friend or Foe. Lawful Stupid characters may also engage in it. A We Have Reserves general usually demands it. This is the only tactic of the Smash Mook.
Compare Last Stand, where retreating from some fights would be carried out whenever practical, and Unconscious Objector, where they keep attacking even after they're too beaten up to realize they're doing it.
Inversion is Screw This, I'm Outta Here. See also Leeroy Jenkins. Contrast Super-Persistent Predator. Possible duplication with I Will Fight Some More Forever. Attack! Attack... Retreat! Retreat! is a comedy version when this trope is juxtaposed with Oh, Crap! and becomes Screw This, I'm Outta Here. A character who relies extensively on this can be defeated if the other side knows how to wear them down through either dodging, tanking, or otherwise causing them to waste valuable energy and resources and leaving them open for a decisive counterattack.
Not to be confused with Tora! Tora! Tora!
The "AI in Video Games" equivalent is Suicidal Overconfidence.
