If you sink a knife into someone's neck from behind and sever the nerves running down their spine, you will paralyze them (and cause them to stop breathing). Cutting someone's neck will kill them in a matter of seconds. The rooms are inadequate for modeling this with the standard attack/damage rules, but I'd let a player work for it. If you can successfully sneak up on someone, I'd allow an attack at a penalty (say -20 or so), on which, if they succeed with a reasonable MoS, they kill or paralyze the target instantly. That doesn't mean you won't be spotted, though. Pretty much everyone in Eclipse Phase has transmitters, there's cameras everywhere, likely monitoring AIs, etc. The more valuable an area, the higher the security and the harder it will be to bypass it. In an area with minimal security, a bag that blocks transmissions over the target's head will suffice. As things get more complex, you might need to have a hacker intercept their signals and spoof their transmissions to a patrol monitoring AI and send a little robot to maintain their path. You'll need to hack spimes to disable them, or lure the target into a camera blindspot, as well as find some way to dispose of the body. It's also worth noting that, in all but the most security-conscious facilities, spimes will largely just be for monitoring things like air-quality. They'll have cameras to monitor particularly secure areas. This also all suggests you're infiltrating some sort of established complex and, all in all, a sneaky person has far less to worry about when, say, infiltrating an unsecure location, acting as a counter-infiltrator, or going into somewhere not so well secured, like a camp in the Martian desert or on an exoplanet.