The Plight of the Mixed Mage

    Characters in most RPGs tend to fall into fairly standard gameplay roles. You have tanks, who take damage and protect the party. You have physical fighters, who usually lack flexibility but are good at hitting things hard. You have mages, who use powerful magic that's usually balanced by strict resource-management systems. You have healers and other support characters, who keep the party alive and help it hit harder. Each of these categories has smaller and smaller sub-categories--you could, for example, divide physical fighters up into ranged and melee, and then you could further divide your ranged fighters up into bow-users and firearm users, and so on--but in most games characters tend to fall neatly into one of these roles (although some games will divide up the healing and support roles across every character, giving each character a bit of supportive utility in order to eliminate the necessity of running a dedicated healer).
    Every now and again, though, you run into something called a mixed mage--sometimes referred to by other names, like "hybrid magic user" or some such--which is a character who is built around using both physical and magical attacks. Mixed mages are a style of character I've developed a fascination with in recent years, partially because (unlike more traditional character styles) they tend to be drastically different in each individual incarnation. Unfortunately, they're often also rather weak. It's difficult to make a "good" mixed mage, so I thought I'd delve into why the character type often falls flat, as well as ways to make it work well.

A Jack-of-all-Trades in a World of Specialists

    Turn-based RPGs tend to reward specialization. In most turn-based RPGs--and especially in those with significant customization options--the best characters are usually not those who do multiple jobs, but rather those who do one job really well. This depends heavily on the game, of course, but in many games the turn economy--the way you utilize time in battle, essentially--doesn't leave characters with much time to be doing things aside from their primary intended roles, especially if you're looking for optimal play. You want your physical attacker to be attacking, your spellcaster to be casting, your supporter to be supporting, and so on.
    This means it's fine for a character to be amazing at one thing and terrible at everything else, as that character should really only be doing one thing regardless. Your other party members take care of the other tasks, and if each party member is doing the one thing they're amazing at, your party as a whole works well. A character who is pretty good at two things--attacking and using magic in this case--weakens the party as a whole because the character is likely only doing one or the other, at which point you'd be better off slotting in a dedicated attacker or a dedicated mage, depending on how you're using the mixed mage.
    This assumes, of course, that the generalist is weaker than the specialist at the specialist's focus area. It's possible that you have a mixed mage who's better at both physical attacks and magic than the specialist, but this creates a separate problem in that your specialists no longer have any purpose, and it also leaves the mixed mage as "someone who can function as an attacker or a spellcaster" rather than "someone who fills both roles at once." So long as you can only take one type of action at a time, you're still better off using the mixed mage as if they were a specialist, especially when equipment options and whatnot usually prioritize one stat type over the other. This simultaneously leaves the game feeling unbalanced and defeats the whole purpose of having a character with mixed skills.

Why Not Both?

    This may seem like an insoluble problem. If specialization is almost always better, how do you differentiate a generalist in a meaningful way? The most successful mixed mages, though, tend to solve this with a little bit of creative thinking. The simplest and most elegant solution I've seen is to make it so that attacks scale off of both magical and physical stats at the same time. This has two notable outcomes: first, it means a balanced stat spread can result in powerful strikes on par with specialists, and second, it eliminates the need for a mixed mage to choose between physical strikes and magic, as both are used concurrently.
    A particularly interesting example of this is Bravely Default's Spell Fencer class. The class applies spell effects to physical attacks, increasing the damage of those physical attacks when used. A Spell Fencer casts a spell on his or her weapon of choice and then attacks normally, benefiting from both physical and magical attributes simultaneously. Bravely Default's customization functionality lets you use this ability on other classes as well, allowing you to effectively turn any physical-oriented class into a mixed mage (and in a more productive way that just giving them access to traditional spells they're unlikely to have any use for). It's possible to create unit builds in this way that are comparably powerful to magical or physical specialists while also retaining the unique flavor of the physical/magical hybrid.
    Tales of Xillia also provides an interesting answer to this dilemma. The Tales games are action RPGs rather than turn-based RPGs--which is to say they play out in real time rather than in turns--but they feature traditional-RPG-esque parties and character builds regardless, with strong delineations between physical attackers and casters. Physical attackers tend to favor faster, weaker attacks that activate immediately, while casters use spells that do a lot of damage but have long charge times. These styles seem mostly incompatible, but one of Xillia's playable characters, Milla Maxwell, is both at once. Milla has access to both reasonably strong physical attacks and standard slow-activating spells, but that in itself is not what makes her interesting. She has a unique mechanic called "spell shifting"  that lets her use her spells without charging them first. When she casts a spell in this way, it is considerably weaker than normal and executes immediately, functioning similarly to a standard physical attack. This allows her to intermix physical attacks and spells, seamlessly leveraging both of her stat pools in a way that's very fun to play.
    Mixed mages also tend to fare well in games that reward having access to wide ranges of tools at once. The Megami Tensei franchise, for example, tends to heavily reward targeting enemy weaknesses--using fire on an ice-themed enemy, for example. While the exact form of these rewards varies by game, it's usually significant enough that you're well-advised to bring allies who can cover a wide range of potential weaknesses. A party member who, for example, has exceptionally powerful lightning attacks may be less valuable (especially in the early- to mid-game) than one who has a mid-strength lightning attack along with two other elements and a decent physical skill. These games have flexible enough customization that "character roles" aren't usually as hard-and-fast as in other series, but the games' tendency to reward flexibility and punish specialization makes specialists less appealing unless you're preparing for specific fights instead of building general-purpose teams.
    These aren't the only strong examples of mixed mages, of course, but they showcase different ways in which the character type can be made to work in satisfying ways, both by combining use physical strikes and magic--in the first two examples--and by disincentivizing specialization and ensuring there are advantages to generalization--in the latter example. Properly-executed mixed mages tend to be a lot of fun to use, as their breadth of options leads to interesting tactical decision-making (on top of just being cool), so it's always exciting to me when developers play with the concept. Even if it doesn't always work, the ones that do tend to be the highlights of their games.