I'm a fan of a lot of the things Eve Online has done, and this is very much applicable here without damaging immersion. I agree that it would enhance the value of human life greatly. You don't necessarily need to take it to the level of repairing Hinds, either, if you want a more subtle impact. Example: You find a book about medicine. While you have it in your inventory, you're able to "research" medicine (the verb used in Eve.) It takes 4 hours (or whatever) of being logged in and alive to learn the skill. Once learned, it opens up more medical recipes with slightly better results. E.g. you can use improvised materials for things like IVs and transfusions with less risk of getting sick. Once illness and health mechanics make it further, you could have the medicine skill reduce the time it takes to fix hypothermia. Notes: In Eve, you don't have to stay logged in to research, so months for high level battleship stuff isn't unreasonable. In DayZ it makes more sense to be logged in to learn, since it's a survival game. You can't just log and learn things, you need to survive the wilds of Chernarus for 4 solid hours after finding the book.Optionally, it could be like eating where there is an animation and you are otherwise indisposed. Then it could only take an hour of "reading," but reading involves sitting down with the book in your lap, making you vulnerable and requiring interruption to go find more food or hightail it.If these "skills" only open up new recipes or make things slightly more effective, you can lower the effectiveness of existing actions slightly. Maybe without a weapon care book, a cleaning kit is only 80% effective, meaning your gun will slowly become ruined despite cleaning it religiously. With the book skill learned, a bandit group has reason to keep you alive to clean all their guns instead of just murdering you, since they probably don't want to take the time to read books instead. If in the future, a splinted fracture means you can't run until it's healed, medicine-skilled splints could take less healing time.Recipe-based incentives open up bartering with other survivors. Trade a good splint for some campfire jerky that won't go rotten. If any skills make it into the game, I see this as being the closest to retaining the hardcore survival feel while opening up player-driven gameplay options.