A key component to any tabletop roleplaying game is how to determine the difficulty of a given action or resisting an effect. There is a lot of space given to "saving throws" and their importance in this text, but how are they calculated? There is a time honored method (and one I adhered to for a long time and still recognize the merits of) of finding a unique DC for each thing that happens in the game. This allows for granularity and the weighing of many factors, but I have found that the time spent doing this is not worth it. That sentiment will vary among game groups and, like all the rules in this book, are subject to modification. For the purposes of this text, however, a simpler method will be used: areas have DCs.
Each area (or section of it if there are drastic changes within the same area) has its own global DC. A relatively safe place will have a DC of 10. This means that Basic Work, ability checks, and saving throws taken here must meet or beat a 10 in order to pass. Crucially, this is also the number that must be met or surpassed to hit enemies in that area. Does this feel too restrictive? You're right, it probably is. That is why at the GM's discretion, or due to excellent roleplaying by the players, rolls can be made "Easy" or "Hard" or made with ADV or DISADV (see above).