I'm a new GM running a Savage Worlds game, and I'm wondering if someone can help me understand the best way to set up a skill check with relative difficulties. Specifically, how do you differentiate between different "challenges" to the same skill?
For example, a "jailbreak" scene: a bunch of prison cells, all locked, with a chest elsewhere that holds the cell keys. If a character has Lockpicking on a d8, they'd be just as likely to be able to pick the cell door as the chest. But that doesn't really make sense, nor does it work for gameplay: picking the chest should be harder, as it negates the need to pick all the cells individually. (In-universe explanation being that the lock on the chest is more complex, or a special design).
How do I differentiate between the same action being "harder here, easier there"? It's easier to Intimidate this scholar than that soldier, it's harder to Ride this warg than that horse. Would I have players roll their skill at a -1 or +2, etc? Or maybe special cases become opposed checks, your Riding versus the warg's Spirit or something?
What's the best/approved/official way to handle these distinctions? Or should one shy away from those distinctions altogether, and just let a lockpick be a lockpick?