[quote=@Polybius]
You got my interest. Could you expand on what magic is like in this setting? How it works, limitations etc.

Thinking of a magic user operating outside the laws and permits you mentioned, maybe on the run from a bounty hunter and needs to disappear for a bit.
[/quote]

Excellent question. I haven't really thought super hard about it yet. What I mostly want to avoid is that magic nullifies the challenges that come with a desert environment. So being able to create food, water or resources out of thin air is a no go.

What I am thinking off right that magic can manipulate the world as it is but not add to it. You can use magic to breath under water because there is oxygen in the water. Then you manipulate your body to extract oxygen from water. You can't use magic to breath in space because there is no oxygen.

Or you can create a barrier to stop bullets by manipulating and compressing a not of air into a tight space in order to create so much resistance that the bullet loses momentum. Ofcourse there has to be air to work with as you can't create.

Or casting fire magic might work by bending the natural occuring combustible gasses in the air to a spot till the point that enough flammable material is gathered to combust.

Using magic should come at a price. It should not be something that can be used all day long without consequences. Maybe it just consumes the energy of the caster, making him more fatigued and requiring more rest food and water to recover. That way it becomes a decision to use that big powerful spell while the next place to rest is 4 hours away and the party really needs to get there before the sun sets too high. 

Magic is a skill that people acquire through study and training. Magic users proberbly have some form of inborn affinity to perceive the world in a different manner. There are legal institutions for training magic users but there is definitely an illegal circuit as well.

That is what i just came up with after reading your question. I'm open to suggestions as well :)