Survival was the ability to survive, particularly in the wild, such as in a forest or desert where one may have found themselves far removed from civilization.
The skill required a variety of other skills to be successful, such as the skills of hunting and tracking.
Cooking was also a useful survival skill as it allowed one to cook any animal that one might have killed during a hunt. Of course, in order to cook, heat is required, so the ability to make fire by rubbing sticks would also be a handy skill. This was an old Indian trick that Apache Chief no doubt learned while in his tribe.