The more variety there is an asymmetric game, the harder it is to balance. When each character (or faction / race / deck / etc.) is extremely different from the rest, there's more potential for some characters to do things that other characters just can't handle. But having radically different characters is really interesting, so is there some way we can keep things balanced anyway? The fighting game series Guilty Gear shows us how.

How They Did It

They handled offense and defense differently.

Universal Defense: all characters have equal access to an unusually large number of safeguards and defensive abilities. This includes failsafes that solve problems the designers didn't have to specifically know about ahead of time.

Unique Offense: each character has unique mechanics that stray further from the standard template than they would in most other fighting games.

Because the designers can count on all characters having so many ways to get out of trouble, they can give each character radically different offensive tools. I think of features shared by all characters as the "design skeleton," and the different options each character has as the "meat on the bones." Even though all characters share many defensive options (and a few offensive options), they feel extremely different. That's because your offense options define your gameplan—what you're actually trying to do when you play.

How different are we talking? The characters in Guilty Gear are more different from each other than the characters of just about any other asymmetric game that I know of, yet the series is still reasonably well balanced and definitely suitable for tournament play. The characters have such different mechanics that sometimes they feel like they're from different games. Here's a quick sample:

Zato-1 lets the player control a second character at the same time as the main character.
Venom can place pool balls on the screen and change their arrangement and trajectories in complex ways.
Faust can throw random items onto the screen and he has to take advantage of whatever he happens to get.
Jam has to summon "cards" in order to power up her moves
Johnny has a limited number of coins per round, and hitting the opponent with coins charges up his "mist finer" attacks. He can also throw a mist onto opponents that makes them unable to block "mist finer" attacks.
Robo-Ky has his own unique super meter as well as a heat gauge that fills as he does moves, and a way to let off steam so he doesn't overheat.
Bridget can throw a yo-yo around the screen and then return it, turn it into a floating razor-bear, and many other tricks.

The Design Skeleton

The reason Guilty Gear is able to have such diverse characters (that are still well-balanced) comes from the common set of things all characters share. Let's look at some of those things, staring with the most basic.

The Basics

With only a few exceptions, all characters have access to this suite of movement abilities and basic attacks:

Double Jump
Ground and Air Dash
Sweep Attack
Overhead Attack that Launches
Ground Throw and Air Throw
Air Recovery (aka "tech recovery")
The ability to block high and low

There aren't any characters who can't block low, for example. There also aren't any characters who can't jump, or who can't walk forward. Characters lacking such basic things would inevitably cause major balance problems, so Guilty Gear wisely avoids doing that, but then so does just about every other fighting game.

Getting Out of Trouble

Some character is attacking you and doing whatever crazy and unique thing that character has. What do you do? No matter which character you are, you always at least have these options.

"f+p" invulnerability. Every character has a move performed by holding forward on the joystick and pressing the punch button. For every character (except Testament), this move grants some invulnerability to the upper body. This means that if an enemy jumps in at you, a f+p move is very good "anti-air." That is, it works well against attacks coming from above (unless the enemy expected it, and double jumped).

Green Blocking (aka "faultless defense"). While you are blocking, if you hold two buttons down, your character becomes surrounded by green rings. During this time, your super meter depletes, but you will take no "block damage" as you normally would from projectiles and other special attacks. Also, when you green block an attack, you will be pushed farther away than you normally would. This allows you to loosen up your opponent's traps by pushing them too far away. You can also use green blocking while you are in the air to block attacks from an opponent on the ground (you can't block those types of attacks without green blocking). Green blocking allows you to get out many situations that might be potentially brokenly oppressive, but it does cost you in-game resource (super meter) to do.

White blocking (aka instant blocking). If you block an attack at the very last moment before it hits you, your character flashes white. This reduces your character's blockstun, meaning that you recover from blocking slightly faster than you otherwise would. It's difficult to time a white block correctly, but it can help you get out of a sticky situation. If there's some sequence of repeated moves that you have to block, white blocking might let you recover just fast enough that you can interrupt the next incoming move.

Alpha Counter (aka "dead angle" attacks). While you are blocking an attack, you can perform this maneuver to cancel your blockstun with a pre-set attack of your own. It costs a lot of super meter to do, so you can't do it that often. If you're being overwhelmed by attacks though, blocking and then alpha countering gets the opponent off you. It knocks them down and gives you a chance to start up your own momentum.

Infinite Combo Safeguards

These next several features contribute to preventing "infinite combos." An infinite combo is a situation where once the opponent lands the first hit of the combo, they can continue the combo forever until they win. The more complicated a fighting game is, the more likely it is to have unwanted infinite combos. The designers of Guilty Gear put several systems in place to reduce the likelihood that such combos could exist.

Burst. This is the most blatant failsafe to stop infinite combos: a move that lets you break out of a combo. The game Killer Instinct pioneered this concept, but implemented it badly. Guilty Gear perfected it. While you're getting hit by a combo, you can "burst" out of it to knock the opponent away and avoid being hit further. It's your "get out of jail free card," and every character has it.

You can only burst about once per round. The designers surely knew that this mechanic was so powerful that it had to be closely regulated. If it cost super meter to use, there would be some character who's good at generating super meter and would be able to burst too much. Instead, burst has its own meter. It starts full at the beginning of the fight, and using your burst empties the meter entirely. The meter fills up automatically over time, but the only thing that can affect the speed it fills up is how much you're getting hit. If you get hit a lot, you get it back a bit faster. There's no trick to get it back instantly.

Your burst meter does not automatically refill each round, which was a clever decision. If you're at the end of a round and getting hit by a combo, you might very well choose NOT to burst so that you'll still have that ability at the start of next round. You should only burst if you think it will actually help you win the current round. The overall effect is that you don't see bursts every round because often players save it for the next round. The failsafe is there, but it doesn't get used excessively.

Also, a clever opponent will expect the moment you'll burst and they'll voluntarily stop attacking right before that. That makes your burst whiff, so they can punish the recovery of it with an even bigger combo. Even the failsafe itself has a counter.

Guard Meter. Right under your health meter is a little red meter called the guard meter. It starts at 50% full, and naturally tends to wander back to 50% if it gets higher or lower. The more attacks you block, the higher that meter gets. The more attacks you get hit by, the lower that meter gets. The higher the meter is (the more attacks you recently blocked) the less you benefit from the game's normal system of damage scaling. Usually, when you get hit by a combo, each successive hit is "scaled" down in damage more and more. But when your guard meter is high, even an ordinary combo can do massive damage to you because you are not being protected by the usual damage scaling. This is meant to punish overly defensive players.

On the flipside, the lower your guard meter is (meaning you got hit by a lot of attacks in a short period of time), the more damage scaling you benefit from. A very, very long combo will eventually do only one pixel of damage per hit because of this feature. So even if an infinite combo did exist, it would take an incredibly large number of hits to actually kill you and you could probably burst out of it before then.

Furthermore, you receive another even more important protection when your guard meter is low: reduced hitstun. Every time you get hit by a move, you are briefly stuck in a reeling animation where you can't do anything (except burst). This is the basic concept that allows combos to exist at all, since the opponent can often hit you again before your hitstun ends. But in Guilty Gear, the more you get hit, the shorter your guard meter becomes, which then makes your hitstun shorter. So if there exists a combo that is a "loop" of repeated moves, it may be possible to do 3 or 4 repetitions of the loop, but eventually the opponent's hitstun becomes so short that the combo simply stops working. (They'll be able to block at some point.)

Progressive Gravity. The longer your character is being juggled by a combo in the air, the greater the force of gravity on your character becomes. Many infinite combos in fighting games involve "juggling" a character in the air with attacks. Much like with actual juggling, it is a fight against gravity to keep it all going. While it might be possible to do 3 or 4 repetitions of a juggle loop, eventually the victim's body falls so fast to the ground that the juggle is no longer possible.

Summary of Mechanics Shared by All Characters

Every character has upper body invulnerability with their f+p move (except Testament). That alone is a great help in stopping attackers. White blocking can get you out of some situations without spending any super meter, but it requires precise timing and has only a small effect. If you're willing to spend super meter as a defender, you can green block or alpha counter. Green blocking will protect you from all damage while you block (except throws) and it will push the attacker away from you. Alpha countering is another method to get the attacker off of you, and it can be performed while you are in blockstun.

That's a lot right there, but there's plenty more. If you actually get hit by an attacker, you have all sorts of things going for you. Your guard meter will eventually reduce the damage you take by the combo and shorten your hitstun allowing you to escape. Increased gravity will also eventually thwart their combo. You can nip it all in the bud, though, by simply bursting right at the very start of their combo, avoiding almost all damage. And don't forget that a great way to nullify attacks is simply not to be in the way of them. Every character can double jump, and every character but one can air dash.

The Freedom to Design Crazy Attacks

Every Guilty Gear character has a lot of options and system features that help them escape or avoid degenerate situations. The beauty of it is that the designers didn't need to know what those situations even were. They don't need to know which combo could juggle forever, because no matter which one it was, progressive gravity probably stopped it. They didn't need to know which non-juggle combo went on forever either: the guard meter's reduced hitstun solves that.

This gave the them the confidence and the ability to arm each character with pretty extreme and wildly different mechanics while maintaining reasonable balance. So that's the recipe: a robust, shared system of defense and failsafes with diverse and unique attacks for each character.