Streamer T Ronix set himself a pretty tough challenge: to beat Fallout 4 without being hit even once. Oh, and without using chems, power armour or companions (unless the story mandated it) either. If he got hit or broke those rules, he’d have to go right back to the start.
It took him over 25 hours (on this, the “8th or 9th attempt”), but he did it. No hits. Not even a glancing blow (though he does die once from hitting a glitch). Which sounds insane, but T Ronix warmed up earlier in the year by finishing the game without healing, so this is just a progression of his skills with the game.
The key was in basically knowing exactly what he was up against in every major encounter, so that he could prepare by taking things out in a good order, packing the right equipment, etc. Oh, and sneaking. Lots of sneaking.