Any comparison to a magic system makes me nervous,...
Martial or magic, from the perspective of pure mechanics, it all boils down to resources. Of course, there are many dimensions to resources which can be used to differentiate them, for example:
How do you gain resources?
How frequently do you gain (or regain) resources?
What can you use resources for?
Change any of the answers, and you get (at least from a surface perspective) a new resource management system.
A Vancian wizard, for example, has the following answers:
- Spell preparation after a long rest
- Daily, after a long rest
- Preparation of arcane spells
A 5e sorcerer's answers are slightly different:
- Automatically, after a long rest
- Daily, after a long rest
- Spontaneous casting of arcane spells; additional benefits once a fixed number of resources are expended
A 5e fighter's answers are more different:
- Automatically, at the start of his turn
- Once per round, at the start of his turn
- To activate martial maneuvers
A simple tweak to the way in which the resources are used, say, by allowing the character to accumulate resources and spend them all at once to create a more significant effect, or the ability to donate resources to other characters, could create a seemingly different resource management system that models a warlord's tactics and leadership:
- Automatically, at the start of his turn
- Once per round, at the start of his turn
- To activate martial maneuvers; may also be used to add to the effectiveness of an ally's maneuvers, or to allow an ally to use a maneuver he knows; may be accumulated and spent to activate more resource-intensive Tactical Abilities
Similarly, a tweak to the way in which the resources are gained, say, by being hit or by missing an enemy, could create another seemingly different resource management system that models a barbarian's rage:
- The character is hit or misses a target
- Each time the character is hit or misses a target
- To activate martial maneuvers; may be accumulated and spent to activate more resource-intensive Rage Abilities