[What's the value of balancing your game, and how do you do it? 100 Rogues developer Keith Burgun tackles the issue of game balance, bringing to light insights that aren't entirely obvious, and showing where game balance really counts.]
The slang term for "imbalanced" is heard frequently in online games, particularly in competitive games. Often, claims about "imbalance" come from a person who just lost such a game and is attempting to save face by placing the failure on the game and away from himself.
Usually, it is actually a combination of these. But sometimes, it really is just the game's fault. Balancing a game is a challenge that man has struggled with for thousands of years, and the battle continues in the realm of digital games.
The previously mentioned "AWP", for those who don't know, is a weapon in the super-popular online first-person shooter Counter-Strike. My personal opinion is that the gun is overly powerful; it's the only gun in the game that seems to be a one-shot kill, no matter where it hit you, whether you're wearing body armor, or behind how thick a wall you were hiding.
While I'm certainly not alone in thinking that (browse some servers on Steam and you'll see about a third of the active servers include a "no AWP" house rule), the debate continues to rage on.
Plenty of counter-arguments have been offered for why the AWP is indeed in balance with the rest of the game, but at the end of the day, it seems like it comes down to my opinion versus yours.
That's a major reason that balance in game design is so difficult to achieve -- it can be so difficult to perceive. There aren't always clean-cut, mathematical ways to balance your game; at the end of the day, it tends to come down to an educated guess on the part of the designers.
A game being "balanced" is also always, at best, a rough approximation. No game is truly perfectly balanced -- even in chess, one player gets to go first. A game being "in balance" is like a person being "in shape"; there's no strict, defined line at which a game goes from being in balance to out of balance, it's a gradual continuum.
Another thing that makes the task difficult is when you have to balance elements that function completely differently from each other. For example, if you're balancing an RTS, and the only thing that changes is attack damage and price, you could easily scale one up and one down when creating new units, and as long as you scaled them at the same rate, you could count on being pretty close to balanced.
Now, let's say we're making a kart racing game. In this game, there are several characters that each have their own ability. One character has an ability that allows him to fire a rocket to knock another kart out for a second. Another character has an ability that gives him a temporary speed boost. These are two abilities that function totally differently; there's no way to look at the numbers on paper and know what would be balanced. In a situation like this -- which is by far a more common situation than the first example -- all a developer can do is guess and check.
Gameplay is all about making choices and in a poorly-balanced game, many of the choices available to the player are essentially rendered useless. And this, in a nutshell, is why game balance is so important -- it preserves your game elements from irrelevance. In an imbalanced game, one or more "dominant strategies" quickly emerge, limiting other strategies useless except for some un-intended purpose (such as getting used as a handicap mechanism, or comedic reasons).
An example of this would be the "tiers" in competitive fighting games. There are usually three or so tiers of characters, with those characters agreed by the community as being "the best" in the top tier. Assuming that a player is attempting to win the game, choosing any of the characters besides those "best" characters is simply not a viable option.
Before I go on, I think it's important to be clear about what I mean by "dominant strategy". A dominant strategy, in the context of game design, is something that emerges due to game imbalance. A clear example of dominant strategy would be "blocking the opponent from getting three in a row", in Tic-Tac-Toe. That's a game that is rendered completely un-playable due to the obviousness of the sole strategy actually available to an aware player. This is the same way that dominant strategy damages or ruins games (although rarely to the same degree).
Characters in Street Fighter II, or weapons in Doom, or units in Civilization are examples of balance at the "elements" level. Sometimes, elements can seem imbalanced in a game when you're not looking at the whole picture. Many times, I've seen an extremely powerful element in a game, and initially said to myself, "Wow, that's gotta be over-powered!", only to find out later that there was a weakness to the element that wasn't immediately clear (the opposite happens a lot, too).
It's easy for a new player to think that Huntresses are an overly powerful unit in the early game in Warcraft III, but once a player realizes their subtly high costs, subtly high food counts, (and not-so-subtle way they get utterly ruined by Piercing or Ranged damage), they realize that they are paying a big opportunity cost by investing in a large amount of them. This is the type of balance that gets the most attention with most gamers.
There are so many areas in which imbalance can crop up, though. Let's take Warcraft III -- a game I played very intensely on the ladder for many years -- as our example. Firstly, you want to make sure that the races (factions of unit-types) are balanced, so that regardless of which race the player picks, they are not at a disadvantage. Then you need to balance the units inside the race against each other. When the game first came out (Reign of Chaos), spellcasters were too powerful, and so every battle was just a ton of spell casters versus another ton of spellcasters, regardless of race.
You also need to make sure the maps are balanced. You might at first say, "Well, that's easy! They just make the maps a mirror, and you're done!" But this is not so. You need to make sure that there isn't a dominant strategy for the map; so, expanding, creeping, attacking, and any kinds of sneaky attacks -- all (or at least most) of these need to be equally viable. That's already a lot to balance, and yet it's the standard for the modern RTS!
Then Blizzard added about five other mechanisms on top of that that needed to be balanced! Creeps, Items, Heroes, and even the competitive ladder itself all needed to be balanced. If you watch just a handful of Warcraft III replays today, you'll see that the game is clearly not balanced, as there are very clearly dominant strategies that get used over and over again. Balance is most likely the sole reason why the original StarCraft, which came out years before Warcraft III, is still more widely played and beloved by the community.