How to balance your map

People keep asking on the forums how to make their maps popular. Blizzard then, told us on BlizzCon that the secret for a good map is to find the fun factor. However, to better achieve this fun factor, the map must be balanced.

Balance is the art of examining the game carefully in order to make it fair between players and game mechanics. A custom map can have an interesting story, sound, artwork, and gameplay; but, if it is unbalanced, it becomes frustrating, boring, and unfair. To describe a lack of balance, the players usually say that the map is “incomplete” or “broken.” Due to the huge variety of maps on Battle.net, there are many distinct ways to obtain balance.

Here are some hints to help you balancing your maps.

Balancing the Terrain

An easy way to make the map fair for all players is making it symmetric. A symmetrical map is made up of exactly similar parts facing each other. Traditional board games, such as chess, use this strategy to provide fairness. For abstract games, symmetry works well. A basketball game, for example, is symmetric, but not perfectly symmetric because one team must start with the ball. Still, the players don#'t even consider this as an unbalance since it is a minor issue. Maps like SotiS, MAD, and Nexus Word Wars used this technique to give both teams equal chances.

Symmetry is important to make a map balanced, but it is also a problem for realism and aesthetics. To improve aesthetics, the choices available for the players can be different while they still have the same functionality. For example, in a symmetric battlefield where the players start the game behind a truck, one side of the field can have a train, instead. Both the truck and the train have the same functionality (hide the start location of the players), but they are not equal. This is called “functional symmetry” and is being used to differentiate the teams on Blizzard Dota.

Functional symmetry is sometimes too obvious and as such is not the answer to all terrain balancing. Some maps are not supposed to be symmetric, such a Risk map. Asymmetrical terrains give different choices for the players to better simulate real-world scenarios and events. Setting asymmetrical forces against each other creates an interesting situation that can be challenging for the player. However, it is difficult to calculate whether or not an asymmetrical map is fair for all players. Letting the players choose their position in an asymmetrical map does not justify the imbalance.

The best way to balance an asymmetrical map is measuring the players’ chances to succeed and improve the game mechanics until the player’s chances match with the expectations. It is a process of gathering data to analyse game balance. Several games must be analyzed with many different types of players (from beginners to experienced players). The average of success of these analyzed games can give a good estimate of how much chance a player has to succeed. In a balanced map, each player has the same chances to win, even though they have completely different choices and styles of play throughout the course of the game.

Balancing Units

The easiest way to balance units in any map is through rigorous play-testing. You are essentially creating complex objects and putting them in a highly complex environment. What this means is, each unit you create has hundreds of different features, statistics, abilities etcetera. The environment you put this unit in, is as complex as the combined total of all the other units in this environment.

Having said this, there are a few things you can do as you create a map (and custom units) to minimize on the need for playtesting and later balancing. I say minimize, because balancing is EXTREMELY important for any game design.

Keep it simple. Avoid having lots of different units, with lots of different custom abilities. Create a handful of units, with a few abilities and balance these first. Then add new units into the environment. As you test the map more frequently, you get a feel for the environment and units which are very over-powered are quickly weakened.
Balance everything. As mentioned above, there are hundreds of ways to balance a unit. Cost, damage, attack speed, abilities, movement speed, upgrades, build time are all just a few of the total number.
The Hard-Counter concept. This idea follows the 'rock-paper-scissors' analogy. You have three vastly different objects, which all have their own strengths and weaknesses. Blizzard capitalized on this concept for Starcraft 2. You see it in any melee matchup. Take this example: Zerglings beat Stalkers. Stalkers beat Roaches. Roaches beat Zealots. Zealots beat Zerglings. To simply balance units around this concept opens up entire strategies and tactical choices for your audience, and that is ALWAYS a good thing.

Balancing Game Difficulty

Note: Applies only for Co-Op vs. Ai games.

It is very important to strike a balance in the difficulty level of your map. A very hard map causes frustration, and an easy map causes boredom. The most effective way of balancing the difficulty of your map is to have it tested in the early stages with a few friends, privately. Study what strategies they go to, what units do they choose to produce, why do they decide to research X instead of Y. When you sit down to a completely unknown game, you are most likely to be confused and a little bit daunted by the information being thrown at you. It is therefore important to

Start with an easy game, and let the difficulty increase along the game; so that, both the beginner and the experienced player can be challenged. The difficulty has to increase in a smooth way avoiding a hard gameplay between easy ones.
Let the skilled players get through easy parts fast to not get bored.
Have an extra challenge that fits all the players, such as a score system where they can try to beat their own record (you can do that by using banks).
Let the players change game difficulty. But, be careful. This requires more balance. Make sure that you specify that 'Normal' is recommended. And always create the 'normal' difficulty first, before adding a Hard or an Easy. Otherwise these modes will be referred to as Frustrating and Boring, respectively.
Avoid creating more than one map-version. This will cause both maps to suffer in terms of popularity. Try and contain the game-modes you wish to incorporate into one map.

Balancing the Player’s Choices

When the choices are bigger than the player’s desires, they get overwhelmed. When they are smaller than the desires, the player is frustrated. The number of choices has to match the players’ expectations, and each choice has to be meaningful. Meaningful choices are the heart of interactivity.

Next time you test your map or play another map, count in your head how many times you are forced to make a decision. Pick a race, pick a hero, pick a class, buy starting items, pick a lane, pick a skill... In this example, you are bombarded with choices in the first 20 seconds of a DotA styled map. Experienced players know exactly what their strategy is going to be. But a new player will not know what to do. Try to space out these decision making choices throughout the length of your game. It is very important to make the choices important, but this becomes apparent through either winning or losing the game. You want a player to leave your game feeling like 'Oh, maybe if I tried doing that instead of this'... Because then that Player is 99% guaranteed to play your map again.

Balancing Randomness

A map can be athletic and serious where it requires a good use of players’ skills or more casual and relaxing where there is an element of luck involved. Random elements can be presented in maps that the victory is won by skill, but their effect must be small to not make the game a matter of luck. Skill can be balanced with luck in a game by mixing them, such as rolling a dice (luck), but letting the player decide what to do with the result of the dice (skill). If the map is too random, it needs more skill. If it is too tedious, the map needs more random elements.

A good strategy is to let the players choose whether they will play safe with a low reward or take a risk for a big reward.

Balancing Challenges

A map challenges a player through physical and mental activity. You should plan which challenge will be dominant in your map. Maps that use physical activity focus on dexterity, such as jumping, shooting, and building. Differently, maps that use mental activity focus on strategies and intellect, such as Debates. There is audience for both types of games. Some players like to think in a strategy for hours while others want to relax their brain and shoot zombies. That is why is important to know the game’s audience and what type of people you are expecting to play your map. The type of challenge should be clear for the audience; otherwise, they might get disappointed.

If possible, let the player choose between dexterity and strategy, such as with different characters (one that uses brutal force and spell and another that might require some strategy to be used).

Balancing Co-op and Versus

To compete is a human urge, but cooperation helps the social. In a competitive map, skilled players should beat beginners. So that, the skilled player is satisfied with the fair measurement of skills and beginners can feel very proud if they win. If the map is about cooperation, the game should give the players an opportunity to communicate. Forced communication usually increases cooperation. Another possible way to balance competition and cooperation is letting the players decide what they want or mixing both modes through team competition.

One problem of competitive maps is when the player who is losing gets uninterested and suddenly quits the game. You can prevent this from happening by having surprising victories. This strategy can be seen on the chess map where the winner can check-mate his opponent in a surprising way and end the game. Another way to have surprising victories is hiding who is winning the game, such as in “Mice vs. Cat.”

Balancing the Game time

When a game is too short, the players have fewer chances to develop meaningful strategies. When the game is too long, the players require hours of dedication, they might get bored, and the map might lose popularity. One possible strategy is having time limits to prevent the game from taking too much time.

Sometimes is good to follow the vaudevillian adage of “Leave ‘em wanting more.” In this way, players might be excited to play the map again.

Balancing the Rewards

The players want to see some feedback when they accomplish a difficult task. Rewarding players is a way to tell them that they are doing well. Psychologically, rewards are better than punishments. As an example, games that the player must eat to not lose life (punishment) tend to be less fun than the ones where food is a life bonus (reward). However, punishments are necessary as much as rewards. Taking risks is an exciting and important aspect for the game challenge. While punishing, a player must be able to understand why and how to prevent it from happening again. Punishments that are hard to prevent makes the player feel that the map is unfair. Some common types of reward and punishment are:

A simple alert message saying if the player did well or not. It can also be a sound.
More or less points in the score.
Shortening or prolonging the play.
Allowing access to new parts of the map or forcing the player to come back to a previous part.
Displaying a show or animation, such as a dance of celebration when a character finishes a level or a sad face when the character dies.
Expressing the rewards and punishments to other players, such as a name on the top ranking or a different model for their heroes.
Giving or taking out powers, such as the character’s weapons.
Giving or depleting resources, such as minerals.
Letting the user complete the game or ending the game with a defeated dialog.

One psychological strategy is to make rewards harder to get as the player progresses in the game. This strategy is used on World of Warcraft where the game gets harder and harder to level-up. This strategy causes the players to play for more time. Another strategy is to avoid making rewards a part of the routine. For instance, employees would not see donuts as a reward if they get one every Friday. Surprising rewards are more exiting for the players.

Balancing Freedom

Freedom can make the players bored because they might go to an opposite direction and skip all the action. A controlled experience can lead the players straight to the action giving them a more exciting experience. Of course, freedom sometimes has its advantages. But, you should have in mind that maps that allow more experience do not necessarily make them better.

Balancing Rules

A map is elegant when it is simple to learn, but full of emergent complexity. Emergent complexity is when simple rules are combined along the game creating very complex situations. As an example, Sentry Scramble starts with a simple rule: to survive. As the game goes on, the players realize that they can use spells. The rules of these spells are simple, such as to teleport or create a force field. But, these rules can be combined creating complex situations. For instance, one spell can create a hallucination while other item creates a force field. Combining these rules, it creates a rule that allows a hallucination to be stopped by a force field. The combinations of rules can be complex and there are extra rules required to balance some elements of the game. However, the emergent complexity allows the player to intuitively know all of these rules without the need to memorize them. To conclude, instead of filling the player’s memory with hundreds of complex rules, let these rules emerge slowly and invisibly along the map.

Conclusion

The fun factor of a map can be better achieved when the map is balanced. The process of balancing a map is all about aesthetics. A balanced map creates a huge impact on the player’s expectations. It takes months to balance it, and some map makers fail in publishing a map straight after getting it to work. As a consequence, the game gets popular before being fully balanced.

A good way to identify an unbalance is asking whether or not the map “feels right.” In the process of balancing it, you should start with the most dominant rules. For example, you first find the best distance and speed for a character’s jump before finding the right damage for the weapon. Another strategy is to duplicate the default values and see how unbalanced the map ends up. As William Blake said, “you never know what is enough unless you know what is more than enough.”

Imagine a Dota with one hundred characters, but one of them has a combination of spells and items that cannot be beaten by anyone. Soon, every player in this game will be using this exactly same character until all of them get frustrated with the lack of balance. Game balance is the finest art in map making, and a map without it can be easily reduced to nonsense.

Credit(s)

Thanks to Rodrigo for contributing the content of this tutorial. The original tutorial can be found here.