Well, time to give a bunch of bad ideas.
-When moving into things(or even next to things), one has a chance to stub their toe. Causes massive pain, but no physical damage.
-When handling paper, chance of getting papercuts, which hurt like hell and bleed but otherwise do no (initial) damage.
-When in pain, NPCs and the player might cry out in pain, curse, cry, or whathaveyou.
-If, while having an active mission, no progress is made after a certain period of time, have the mission giver get angry and attack you. If they belong to a faction, the faction also gets angry with you.
-make it impossible to mount a bayonet to a bolt-action rifle. Oh wait, thats actually a thing already…