This is a rather large subject, I know. Variables are the general tech level of the society in question, the general power level of the magic in the setting, how common it is and what magic can affect. And also whether the magic is actually magic at all - Clarke's Third comes to mind.
In the fiction I've seen containing magic, the tech level varies from Stone Age (rare) to interstellar civilisation (Star Wars and 40K) with just about everything in between. Most writers seem to pick something between Iron Age and modern day as a tech base, with a strong preference for mediaeval - Tolkein influence there, perhaps.
Magic power level varies from minor love spells and the like to cosmic - the latter being represented by the D&D setting, Wheel of Time and Young Wizards.
So, let's set up some examples. I mentioned this in another thread, but IMHO the politics and military history of the Roman era would have been drastically affected by some types of magic. A unit of heavy infantry in close order would be rather powerfully affected by large-area blasting spells, even if the damage is minor; think about what an insect plague would do to the unit cohesion of a Roman century, for example.
So if magic is common and reasonably powerful, the Roman army would have to be drastically different. IMHO, of course.
For another example, what would easily available truth-revealing magic do to any society?
In the fiction I've seen containing magic, the tech level varies from Stone Age (rare) to interstellar civilisation (Star Wars and 40K) with just about everything in between. Most writers seem to pick something between Iron Age and modern day as a tech base, with a strong preference for mediaeval - Tolkein influence there, perhaps.
Magic power level varies from minor love spells and the like to cosmic - the latter being represented by the D&D setting, Wheel of Time and Young Wizards.
So, let's set up some examples. I mentioned this in another thread, but IMHO the politics and military history of the Roman era would have been drastically affected by some types of magic. A unit of heavy infantry in close order would be rather powerfully affected by large-area blasting spells, even if the damage is minor; think about what an insect plague would do to the unit cohesion of a Roman century, for example.
So if magic is common and reasonably powerful, the Roman army would have to be drastically different. IMHO, of course.
For another example, what would easily available truth-revealing magic do to any society?