If you've played Uncharted before then, unless you're a ninja, you will have seen red on the edges of the screen when Drake comes under fire from enemy henchmen.
Jonathan Cooper, an animator for the team at Naughty Dog, has shared some insightful knowledge over on Twitter where he explained that Nathan Drake isn't actually a bullet sponge since the red on the screen doesn't represent damage suffered, but the probability that Drake is going to get hit. The more shots fired, the more the enemies adjust their accuracy, and so his chances of being fatally wounded increase.
"That's a mega-swing! Sidenote I learned on joining the team: Drake doesn't ever take bullet damage. The red UI that shows 'hits' is to represent his 'luck' running out. Eventually enemies will get a clear shot and kill him if he takes enough near-misses."
This interesting little revelation was confirmed during the same discussion by writer Amy Hennig, who worked on the first three instalments of the series as well as the episode released in 2011 on PS Vita:
"True! That was the original intention (to stay more aligned with the spirit and tone of the films we were homaging)."