So, the pacifist trait - is a pretty terrible trait to pick, purely because no one who's actually smart at the game uses firearms due to their inaccuracy and loudness. (You can create unmanageable hordes with a few shots; let alone the thousands of bullets that you have to waste to get a decent aiming skill where you don't miss 4 in 5 shots).
So; it's a terrible trait purely because melee weapons are the preferred weapon of choice and no one wants decreased XP for all melee related skills - not a surprise because of their stealthier approach to combat. And the +4 points that it gives you is purely not enough to persuade a smart person who plays the game to survive to pick the trait. So here's my balancing suggestion...
It's safe to assume that pacifists hate violence, right? So how about we add a very minute amount of unhappiness per zombie killed and a drastic amount of unhappiness for murdering a player (or human NPC). This will amount to at least 20-30 zombies killed in a day to get depressed, or be 1-3 humans murdered. This will add a permanent use to the antidepressant pills that are currently in the game; and will be the new smokers' cigarette. Pacifists will have to regularly take antidepressants to forget about the horrors of the apocalypse.
And due to the increased negative effects of having such a trait; the trait should give you +6 trait points, making the trait actually seem reasonable to use.
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