Foolish, foolish mortals and your obsessive need for representation, it can get so bad it hurts. Worry not dear reader, for in the world of fantasy, where at least I go to escape reality, even a wheelchair bound person can become a lean, mean, murder machine. With a couple of simple steps even you can become a bona fide killer. I have realized that people are stuck with what they are, instead of what they could be. Take Dungeon & Dragons for example, a world of imagination, adventure and debatable rules to live and die by. In most cases a cleric can heal pesky things like non functional feet and useless limbs. Miracles, gods and wishes are very much real. Unless your stuck in Dark Sun, then you're most likely dead before you begin.
First of all let's take a closer loom at a wheel chair. It is a lightweight chair, attached to two big wheels and at least two small wheels for turning. Which allow a person to use their arms to push the contraption forward. A modern one is either electric, or made a light weight as possible. However in more primitive settings, it will most likely be made of wood, especially the wheels, thus it becomes quite heavy in the long run. Though that also depends on skill of the artisan crafting the chair.. The lack of rubber and inflated wheels will also make it very uncomfortable to move around. On top of that, getting around dungeons is going to be very hard indeed. Especially when the terrain gets bad. Unless you get really creative, or embrace cyberpunk Caterpillar style threads are out of the question. Not to mention the lack of an engine to propel the contraption in any direction.
However in Dungeons & Dragons, only an uninspired pheasant think about using wheels. Even though a cart is cheap to buy and almost free if stolen. Though in 5e a donkey is act actually cheaper than a cart, which it is most likely capable of pulling. If you really want to be pedantic, modify a wheelbarrow they're most likely worth less than five gold. However let's forget reality for a while, for what is fantasy? But a way to have a merry time and escape from the rules of our reality. Granted being a bad-ass in a wheelchair does have its merits, more on that later.
The most basic thing any sensible adventurer can do is to acquire a mount. Such as the donkey I mentioned earlier. From my personal experience, a donkey is a smooth ride on a stubborn equine, that has a low ground clearance and high carry capacity. Camels on the other hand, now those are absolutely terrible and that is me speaking from personal experience. Like I said, let's forgo reality for a while. Take a giant spider as an example, now there is an interesting mount. Especially for someone that want to strike fear into men and monsters, have decent defensive capabilities and being able to traverse rough terrain. With some creative rule abusing, it can probably be equipped with a chair, or a saddle, then attach zephyr horseshoes. Suddenly you've got yourself a flying spider. Granted a good mage can learn to fly through magic. Or just get a comfy flying broom with a seat on it. After all in Dungeons & Dragons walking is the least interesting way of locomotion. Personally I would get myself a hippogriff or another terrifying beast, that can actually fly. Even if it has to be fed half a cow every day. Essentially the creature is fast and ferocious and capable of defending itself. Which technically can either attack on it's own turn, or use one of riders actions instead. It depends on the rules really.
For the more refined gentle person there exist a more classy alternative exist. The portable chair with two poles attached, which has to be carried by two fateful servants. It is a simple medieval lord favorite, extra bonus points if it comes with a human footstool and a troubadour. A chariot is also a very valid example of a true and tested transport. Unlike a wagon it is small, fast and light weight. But it does leave the beast of burden exposed to attacks. A typical horse is unfortunately very easy to kill, due to low health and few ways to attack. Since most monsters are bloodthirsty killers out for blood. A life giving fluid most horses have a lot of. Unless the clever player dives in to Mordekaines emporium and dig up some fancy figurine that turn into a mount for a time.
Particularly evil characters will use skeletons and the reanimated dead to move them around the word. There is always the mind control option, thralls and various infernal beings.
Let us look at the generic wooden wheelchair, which is lighter than steel and cheaper than fancy lightweight material like mithril or admantium. It will be fairly heavy and rather uncomfortable to actually move around, plus oak wheel have terrible shock absorption. Essentially the user would feel every bump in the road and a pillow only absorbs so much of the impact. It might be fantasy, but gravity still exist. Combine this with armor and it will get even worse to push around, because a high armor class will make up for the lack of dexterity. Because using the arms a lot makes a person strong, unlike a sissy rouge skulking around in the shadows. For extended reach a polearm is an excellent choice, especially with attack of opportunity, then very few things can get behind the wheelchair warrior. An additional design feature that comes highly recommended most would not think of is some kind of rest for the weapon, when switching between moving and fighting.
Since this build will be heavy and unwieldy, some sort of servant is needed to push the wheelchair. A human is a cheap and unreliable choice, but at the start of an adventure that is the most likely the only option. But a human is very weak and most likely very squishy. The more advanced and stubborn wheelchair bound adventurer will invest in a golem. A simple construct that follows basic commands and is good at manual labor, it can also crush smaller creatures and defend itself. A war forged one is a couple of steps above that and most likely a player character, which would lead to some amazing synergy. Essentially the wheelchair warrior wields a sharp pointy sick and a shield, while the golem pushes the player into into battle. Yes, I am imagining wheelchair jousting hero here and you're welcome.
Outside of Dungeons & Dragons, there is settings such as Mage the awakening. Where a friend of mine made a version of Xavier. A bald mage incapable of walking. In combat he floated around several swords and a shield for protection. But this fellow I a clever little munchkin and made the wheelchair capable of transforming into an exoskeleton. Suddenly the man could miraculously walk into battle, despite having no movement stat.
That is all I have for now, Zaceron signing out