Let's stop and reevaluate this from the most important perspective. The most important thing being gameplay and fun. Whatever "realism" everyone is trying to argue is entirely secondary as just about any infection mechanics can theoretically be explained by some type of virus, bacteria, prion, parasite, resistance, mutation, whatever. As has been said before if you get infected now you might as well suicide. If you are playing multiplayer you just take your good gear, stash it somewhere and have your next character run and get it. Entirely fatal bites/scratches in zombie filled worlds are great for narrative storytelling in movies and TV. Characters try hiding it, fights break out, and we get to watch the emotion filled road to accepting death. In a game, escaping an epic holdout or battle and then finding out you have been bitten is just an anticlimactic end that usually feels lame. The threat of a single person turning into a zombie in multiplayer just isn't a big enough deal for party members to really be too concerned (especially considering that you are probably just going to stash your stuff and then kill yourself somewhere so you can get back to helping your group). So let's look at another option that gives players more choice and excitement: Proposed Mechanic 1. Zombie bites/scratches have a chance of causing an infection, especially if wounds are not treated. 2. These infections are CURABLE. They cause fairly rapid fever and illness which can be debilitating and fatal. 3. Players can try to fight infections with or without antibiotics, with the latter obviously having higher chance of survival. Now if I got bit and infected under these conditions I now have to actually make some decisions since my fate is uncertain. I could decide to run off to the overrun hospital in hopes of getting some antibiotics or if I deemed myself healthy and well off I could try and hunker down and beat the fever. With either choice there's a significant risk of death, but there is a choice and there may not always be a best choice. In multiplayer, instead of just exiling someone or killing someone immediately we now have the added option of taking time out to try to help our companion. Whether that be assisting with scavenging for medicine, using what rare amount the group has, or taking out valuable time to nurse the sick to health. (An option for other players to help manage someones fevers or even feed them at bedside could be interesting, especially if the sickness lasts for days or the player became crippled by it. You would have to really put effort in if you wanted a chance of seeing your friend make it through). So instead of a day or so of boring inevitability we get desperation that actually can create better stories and is more fun for everyone. Would I play any differently or more recklessly now that I know I could be cured of an infection? I personally wouldn't since there's still always the a good chance of death and I really wouldn't want to lose possible in game days sitting around trying to recover. NPC's: This is another chance for NPC's to shine. If an NPC or their party member is sick they would probably become very desperate and willing to trade almost anything for antibiotics (or take them from you). Maybe nursing them to health or helping them out would be a nice way to get a new ally. I'm not seeing a downside here.