
Killing a non-evil character: -100 Karma (although, this can be gotten around by shooting them once, making them hostile, then letting a follower kill them.)(note).
Performing an evil action in a quest: At least -50 Karma.
Giving away Aqua Pura with the modified FEV with Broken Steel installed, to beggar characters like Carlos outside of Rivet City: -50 Karma per item. Selling ears taken from the corpses of good characters (you killed) to Daniel Littlehorn via the Contract Killer perk: -10 Karma per ear. Repeatedly hacking an owned (red text) terminal (Classified as stealing, but can be done over and over again) -5 Karma per hack attempt, NOTE, even accessing the terminal will result in negative Karma. Items can be replaced in owned containers after being stolen, and then stolen again and again with the same Karma loss each time, making for a useful method by which console gamers can decrease their Karma, although repeatedly hacking an owned terminal is a faster way of doing this.
Meaning, if you open a container once and steal two items, you lose 5 Karma, but if you open the same container twice, stealing one item each time, you will lose 5 Karma each time, which means you lose 10 Karma).
Stealing from a non-evil character or faction: -5 Karma per instance (note that when stealing from owned (red text) containers, such as cabinets or lockers, the Karma change applies once per activation of that container. Devour a corpse (Cannibal perk required): -1 Karma per corpse. The full list of negative karma actions and their associated karmic impact: This wiki page lists all actions you can take to affect your karma. Enslaving any character with the Mesmetron: (-100). Giving Psycho to Paulie Cantelli in Rivet City (-100). Giving away FEV modified purified water (-50). If we use "donating purified water" as our baseline (+50 karma), repeatable actions that are at least as evil as giving away water is selfless: You'll notice none of those things are repeatable, however. Take the Devil's Highway Perk ( -2000 karma).