Is Your Game Balanced?

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As with 'fun,' the concept of balance is often used to describe the process of making a game 'better.' We offer a specific definition of balance here. Your game may require specific balancing techniques not addressed in this definition. But hopefully this will help you get started, and help you focus your thoughts as you step through this sophisticated process.

'Balancing' a game is the process of making sure the game meets the goals you've set for the player experience: that the system is of the scope and complexity you envisioned and that the elements of that system are working together without undesired results. In multiplayer games, it means that the starting positions and play are fair (i.e., no player has an inherent advantage) and no single strategy dominates all others. In single-player games it means that the skill level is properly adjusted to the target audience. For short, we call these four balancing areas 'variables,' 'dynamics,' 'starting conditions,' and 'skill.'

Resolving issues of balance is one of the most difficult parts of designing a game. This is because the notion of balance encompasses so many different elements, all of which are dependent on one another. Many of the concepts involved in balancing also involve complex mathematics and statistics, which you may or may not be skilled at computing. Don't let that deter you from the process, however. Balancing is as much about gut instinct as it is about numbers-with enough experience, you'll be able to tweak the variables in your physical prototype, or give detailed feedback to the programmers for your digital game without a degree in calculus.

Balancing variables

The variables of your system are a set of numbers that define the properties of your game objects, whatever those might be. These variables may define how many players the game is designed for, how large the playing area is, how many resources are available, the properties of those resources, etc. In the Connect Four example from Chapter 8 on page 217, the properties included two players, a 7×6 game grid, 21 red units, and 21 black units. Indirectly, these variables also determine important aspects of how your game will work when it's set in action.

For example, in Connect Four, when you changed the grid size from 7×6 to 8×6, you had to increase the number of units from 21 of each color to 24 of each color-if you didn't, your players may have run out of units before the game was over. This is because we need enough units to fill every cell on the grid: 8 × 6 = 48, 48 ÷ 2 = 24. Hence, the change in one game variable necessitated a change in another.

Changing the grid size changed some other aspects of Connect Four, which you undoubtedly discovered during your playtest as well: (1) the playing time was increased and (2) the game became less exciting. The reason for the first discovery is somewhat obvious-with more area to fill, players had more options to explore, and less contention for the space.

The second discovery is an interesting and perhaps unexpected one. With eight columns, rather than seven, the game is less exciting. Why is this? In the game with seven columns, the center column is flanked by three columns on each side. This means any horizontal or diagonal row of four units must include a unit in the center column. This places great importance on that center column. The battle for control of it draws the players into conflict with each other quickly and makes the overall experience more exciting.

Thus, the original size of the grid is more successful than the 8×6 grid. We can only learn what scope will be most effective for a system through repeated testing with alterations in the game variables.

Digital games operate under the same principles. In Super Mario Bros., you start with three lives. If you started with one life, the game would be too hard. If you started with ten lives, the game would be too easy. Changing lives changes how the game plays. Playtesters act differently when they have ten lives versus one, so the experience and balance of the game shifts.

Many variables in videogames are hidden in the computer code. This makes them more difficult for us to analyze, but we can conceptualize them. We've already looked at several examples of game variables: the unit properties in the WarCraft II editor (Figure 7.12 on page 171) as well as the map size for the WarCraft III editor (Figure 7.11 on page 170). Although it is not as easy to visualize, the number of resources available at any given time in the world of EverQuest, as well as the running speed and jumping height of a game character like Mario are also variables that can be adjusted to control the experience of the game.

Can you imagine playing Mario if he moved like a slug? It would be boring. Likewise can you imagine if Mario moved really, really fast? It might be frustrating because he'd be too hard to control. Game designers at Nintendo tweaked the numbers for these variables up and down to arrive at a comfortable speed that would appeal to the majority of players.

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Figure 9.5: Connect Four-center column is flanked by three columns on either side

The purpose of manipulating variables all comes back to your basic goals for the game-the experience you are trying to create. You can only effectively judge the viability of your system variables if you have a clear picture of that experience.

Exercise 9.5: Game Variables

start example

List out the game variables in your original game prototype. Make a change in one variable and observe how it affects other variables. This is an opportunity to test how your system plays under different conditions. Can you make easy, medium, and hard levels simply by tweaking the variables?

end example

Balancing the dynamics

When we talk about balancing the dynamics, we mean the forces at work when your game is in action. As we discussed in Chapter 5, when systems are set in motion, sometimes there are unexpected results. Sometimes, a combination of rules creates an imbalance. Sometimes it's a combination of objects, or even a 'super' object that unbalances play. Other times it may be a combination of actions that provide an optimal strategy for player who know the trick. Whatever it is, these types of imbalances can ruin gameplay. You'll need to identify them and either fix the rules that create the problem, change the values of the objects, or create new rules that mitigate the optimal strategies.

Reinforcing relationships

As we saw in Chapter 5 on page 129, a reinforcing relationship occurs when a change in one part of a system causes a change in the same direction to another part of the system. For instance, if a player earns a point, they would be rewarded with an extra turn, thereby strengthening their advantage. This starts a cycle that rewards the stronger player over and over until the game concludes, probably prematurely, with that player the winner.

This type of problem might be solved by changing the reinforcing relationship you've set up into one that balances the power more fairly-for example, when a player earns a point, the turn is passed to the other player, thereby balancing the effect of the point advantage.

Basically, you want to keep the strong player from accumulating too much power from a single success. Instead, they might receive a small, temporary bonus, but nothing that throws the game out of balance. In many cases, designers make the winner pay a price for taking a strategically important position. This tends to balance out the gains, ratchet up the tension, and provide the loser with a chance to come back.

Other techniques include adding an element of randomness, which can come into play and alter the balance of power. This can take the form of external events, like shifting alliances, natural disasters, and unfortunate circumstances. You may also want to enable the weaker players to group together to battle the dominant one, or have a third party intervene.

The goal is to keep the scales balanced without stagnating the game. After all, this is a competition and someone has to be able to win eventually. Naturally, in the last stages of a game, the scales will tip, and when this happens, let the scales tip dramatically. There's nothing as satisfying as a sweeping victory. This makes the winner feel good and provides for a swift, merciful defeat for the loser. You never want to drag out the ending. Think of your game as a movie. Once you've passed the climax, wrap it up fast.

A game that deals creatively with this type of problem is the strategic multiplayer shooter, Battlefield 1942. In assault matches, one team starts with a single spawning point and the other team controls every other spawning point and area of the map. The attacking team must fight to take ground. An example of a map that works like this is 'Omaha Beach' which simulates the D-Day invasion. The Allies start on board a ship and must take spawning points on land from the Germans. Battlefield 1942 incorporates a 'tickets' system. Each side begins with a certain number of tickets that are reduced whenever a player is killed in action and subsequently re-spawns. When the number hits zero, the game is over. However, fulfilling certain victory conditions will cause the opposing team's tickets to slowly deplete, until they manage to reverse the situation by reclaiming a required control point. This gives teams a chance to come back from the brink of disaster, or at least, it gives players the resolve to stay in a losing game and manage a minor, rather than a total, defeat based on the percentage of tickets by which they lost.

Exercise 9.6: Reinforcing Relationships

start example

Analyze your original game prototype for reinforcing relationships. Is it common for the player who gets an early lead to win the game? If so, you may have a reinforcing relationship that is creating an imbalance in the system. Identify the issue and change the relationship to balance the play.

end example

Dominant objects

A good rule of thumb is to keep similar game objects within a game proportional in terms of strength. For instance, in a fighting game, no single unit should be significantly more powerful than the others. 'Super units,' as they're sometimes called, ruin the gameplay by becoming so valuable that none of the other units matter. One of the best ways to keep every element in proportion but still provide a range of choices is to think in terms of strengths and weaknesses. Every unit can be balanced by giving it a special advantage and a corresponding drawback.

Think of the classic 'rock, paper, scissors' game. This game works because each element has a clearly defined power and failing. In this game, two players simultaneously choose one of three items: rock, paper, or scissors. Each item wins, loses, or ties depending on what is played by the opponent. Rock beats scissors, scissors beats paper, and paper beats rock. When illustrated in a payoff matrix, it looks like Figure 9.6.

On the matrix, 0 equals a tie, +1 equals a win, and -1 equals a loss. It shows that the three options balance each other out. This concept, sometimes called 'rotational symmetry,' is often used to balance digital games as well. For example, as Ernest Adams points out in his article 'A Symmetry Lesson' on Gamasutra.com, The Ancient Art of War by Brøderbund was designed so that knights had an advantage over barbarians, barbarians had an advantage over archers, and archers had an advantage over knights.[1]

Many games use this technique in one form or another. In fighting games, each unit or character has his killer moves and Achilles' heel. In racing games, some cars are good at going up hills but handle poorly on corners. In economic simulations, some products are more durable but cost more, while others have a limited shelf life but higher profit margins. Assigning strengths and weakness is one of the fundamental aspects of game design and should be kept in mind whenever balancing gameplay.

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Figure 9.6: 'Rock, paper, scissors' payoff matrix: rotational symmetry

Let's take WarCraft II, in which players can play a human or an orc civilization. The two sides are symmetrical in many respects but have minor differences. Both civilizations have the same types of units and buildings, which yield the same types of abilities. For instance, the humans have a 'peasant' unit that has the exact same hit points, cost, build time, and abilities as the orc's 'peon' unit. The name and the artwork associated with human peasants and orc peons are different, but from a formal perspective, they are identical.

An example of a difference is the orcs' 'bloodlust' ability versus the humans' reciprocal 'healing' ability. Taken only at face value, bloodlust is more powerful than healing. It enables orcs to deal triple damage in battle. A gang of bloodlusted orcs can easily slay a same-sized gang of humans in direct combat. In order to balance out this discrepancy, the designers at Blizzard gave the humans other abilities and strengths. However, the player must choose an appropriate strategy in order to benefit from them. Healing is not very useful in direct combat with orcs, but it can be effective when utilized as part of a 'hit and run' strategy. To do this, the humans must attack the orcs, then retreat quickly, heal their units and attack again. This works particularly well as a strategy for gryphons, because they can fly away.

Humans also have slightly more powerful magic spells than the orcs. However, they also require both skill and strategy to employ. The human mage unit can make other units invisible so they can sneak into an orc camp for a surprise attack. Or the mage can cast a polymorph spell that will change an orc unit into a harmless sheep. Both of these spells are expensive in terms of mana and require the player to execute complex maneuvers, but the payoff is there. Overall, the orcs are more powerful in direct ground combat, but humans can compete through crafty choices and acquired skills. The point is that there are discrepancies between orc and human units, but overall, the game does a good job of balancing the strengths and the weaknesses, which is no easy task.

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Figure 9.7: WarCraft II-Bloodlusted orcs attack a human stronghold

Dominant strategies

Sometimes players can discover one or two strategies in a game that effectively dominate all others. This has the effect of narrowing the number of overall choices in the game, because no one will choose the weaker strategies once the dominant ones are known.

For instance, if one way of attacking is far superior, the players will gravitate towards this method. Even a minor imbalance in this regard can have a significant effect upon a game's playability. When balancing a game, make sure there is ample choice in all areas, and that as the game progresses, nothing limits the players' options. When players focus on only a limited set of options in pursuit of a win, games often become dull.

Can you imagine trying to play a game in which your opponent has already calculated the dominant strategy and simply executed it? The game would be frustrating for you and boring for them. If you both knew the dominant strategy, it would be a rote entry of choices on each of your parts, resulting in an experience that you could have predicted from the outset. Tic-tac-toe is a game in which there is a dominant way of playing and thus it isn't an exciting game.

What makes games interesting and challenging is the fact that their systems do not offer a dominant strategy-at least, not at first glance, or even upon repeated play. As a designer, you should always be on the lookout for dominant strategies. When you see one, find a way to get rid of it or obscure it so that players don't simply latch onto that method at the expense of everything else.

One word of caution: a dominant strategy is not the same as a favorite strategy. If hardcore players discover a way of playing your game that they like to employ over and over, but it is not always effective, this is not a dominant strategy. If the game is balanced properly then other players may have ample choice of opposing strategies to counter with.

Balancing positions

In balancing the starting positions for your game, the goal is to make the system fair so that all players have an equal opportunity to win. This does not always mean giving each player the exact same resources and set-up. Although many games are symmetrical in this way, just as many others are not. As we saw in our discussion of player interaction patterns in Chapter 3 on page 44, there are various and interesting ways to design the competition in your game-a symmetrical competition is only one.

Additionally, the challenge of balancing multiplayer games is different from that of single-player games. This is because single-player games often involve a computer 'player,' or AI that competes against the human player. To understand how this affects balancing, let's look at two basic models for multiplayer games: symmetrical and asymmetrical.

Symmetrical games

If you give each player the exact same starting conditions and access to the same resources and information, then your system will be symmetrical. In chess, black has the same sixteen units as white, opponents start in a mirror-image configuration of each other on the board, and opponents have the same amount of space on the board to maneuver. Connect Four, Battleship, Othello, checkers, Go, and backgammon are likewise symmetrical systems.

In turn-based games like the ones just mentioned, there is one asymmetrical aspect that must be dealt with. It is the issue of who moves first. This issue could throw off the fairness of the game if not balanced correctly. In his article on symmetry mentioned previously, game designer Ernest Adams points out that you can reduce the effects of one player going first by establishing a system where the first move provides little strategic advantage.[2] Chess is set up so that only the pawn or the knight can move at the opening. These are two of the weakest pieces in the game. Additionally, four rows separate the opponents at the opening, which means neither side can threaten the other with the first move.

Exercise 9.7: Dominant Strategy

start example

In your original game, can you identify a dominant strategy that limits player choice? If you can't find one, list out some strategies that do work. What are the opposing strategies that players may utilize?

end example

Another option is to balance the system so that a game takes many moves to resolve. This renders the first move of little strategic significance. Chess is a fairly long game; so going first has little effect over the course of a whole game. Contrast chess with a very short game such as tic-tac-toe. In tictac-toe, moving first is an enormous advantage. So much so that it enables a rational player to always win or tie.

Adams also points out that you could incorporate chance elements to reduce the effect of one player going first. Symmetrical boardgames like Monopoly and backgammon require players to throw dice to move. The dice are chance elements. Since the first player could have a bad roll and the second player could have a good roll, the first mover advantage is mitigated.

Asymmetrical games

If you give opponents different abilities, resources, rules, or objectives, your game will invariably be asymmetrical. An asymmetrical game, however, must still be fair. As a designer, your goal is to tweak the variables so that the system balances out. If played properly, each opponent will have roughly the same chance of winning, regardless of the other factors.

This type of asymmetry is powerful in games because it can be used to model conflicts and competitions from the real world. Historical events, nature, sports, and other aspects of life are full of situations where opponents compete with differing positions, resources, strengths, and weaknesses. Imagine trying to recreate a WWII battle where the players had to begin with the same units on a symmetrical board. It wouldn't make sense. For this reason, the vast majority of digital games tend to be asymmetrical. Let's look at a few games and see how they deal with the issues of asymmetrical abilities and resources.

In the fighting game Soul Calibur II there are twelve different characters, each with its own set of ability statistics. A typical character has about a hundred fighting moves and a distinct fighting style. As in many fighters, a move can inflict a variable amount of damage-from none, all the way up to a kill-depending on the countermove played by the opponent. Each time one character attacks another, a damage payoff is determined for one or the other or both of the characters. Mastering the game requires an understanding of how and when to play fighting moves in different situations against different characters. In this example of asymmetry, designers at Namco balanced a system where opponents have the same objective and same basic movement resources but different abilities.

In the RTS game, Command & Conquer: Generals, players choose one of three different armies: America, China, or an underground terror organization called the Global Liberation Army. Players adopt a playing style that matches the strength of their chosen army. The Americans utilize high tech weaponry, the Chinese swarm opponents with sheer numbers, and the Global Liberation Army relies on cunning and sneakiness. The key to this game is that the armies have different resources that are balanced, so that, if played skillfully, any one of them has ample choices to beat the other two.

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Figure 9.8: Command & Conquer: Generals

Another game with asymmetrical resources is NetRunner. It's a collectible card game designed by Magic: The Gathering creator, Richard Garfield. In this game, one player plays a corporation using purple backed cards, and another player plays a runner (kind of like a cyber hacker), using green backed cards. The cards in the two decks are completely different. The corporation uses cards to build and protect data forts, with the ultimate goal to complete corporate agendas. The runner uses his cards to hack corporate security. He tries to steal agendas before the corporation can complete them. The competing sides in this asymmetrical game utilize completely different resources and abilities, but they share the same overall objective: to score seven agenda points.

Exercise 9.8: Symmetrical versus Asymmetrical Games

start example

Is your original game prototype symmetrical or asymmetrical? Describe how and why.

end example

Asymmetrical objectives

Another type of asymmetry involves offering each player different objectives. This can add variety and intrigue to a game. You can offer asymmetrical victory conditions when opponents are otherwise equal, or you can combine asymmetrical objectives with asymmetrical starting positions for a real balancing challenge. In this case, your motive might be to add variety or evoke a real-life situation. Following are several models for offering asymmetrical objectives. Notice that in each case the differing objectives are still balanced against each other to keep the game fair.

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Designer Perspective: Graeme Bayless

Title

Supervising Producer, Electronic Arts, Tiburon

Project list (five to eight top projects)

Wow, tough list. I've been doing this for sixteen years, and have been involved in shipping over 60 titles. I could go just by raw sales figures, but that's not necessarily the ones I'm proudest of (though I'm certainly proud of them as well). I guess I'll just mix the two. Here are some titles, in no particular order:

  • NFL Street (releasing early 2004, one of the most exciting titles I've ever worked on)

  • Madden NFL 2001, 2002, and 2003 (certainly the most successful titles I've helped lead)

  • MissionForce: CyberStorm (not a huge success, but a fun game that emphasized some design concepts I wanted to explore)

  • Battles of Napoleon (still one of the best reviewed war games ever, 1988 release)

  • Kid Chameleon (old Genesis 'jump and bonk' game-when we designed it, it was the most massive game of its type ever, with 100+ levels)

How did you get into the game industry?

Well, I got in a long time ago (1987) when the industry was still trying to find its identity. I had always been a gamer (I've played games as my primary form of recreation since I was eight, and submitted my first paper-game design when I was fourteen) and thus I spent my weekends at the local game store, playing various paper-games or miniatures games. One day, I noticed a posting on the bulletin board of the store I frequented. The posting was an advertisement for a part-time weekend playtester. I figured, 'Hey, I can do that,' especially since the company was Strategic Simulations Inc., a company that made computer war games which I played heavily. I applied, and got an interview with their manager of testing (who was also their manager of customer service). As the interview went on, she became more and more impressed with my game knowledge, so she asked me if I'd like to interview for their customer support position. I agreed, and came back for another interview. The second interview round included a programmer who was temporarily helping customer support until they could hire someone. This programmer was impressed with my design sensibilities, and suggested I return for a third interview for a 'game developer' position (effectively an associate producer). I agreed, and the next thing I knew I was at lunch with the company president (Joel Billings) and vice president (Chuck Kroegel). The interview went well, and I was hired. I spent the next 30 months shipping about 30 SKUs, operating as the testing department, writing manuals, and participating in design on numerous war game and RPG titles.

What are your five favorite games and why?

It's very difficult to pick just five, but I'll take a stab at it.

  • M.U.L.E.: This was a superb title published by Electronic Arts in 1983. It was simple, yet one of the most elegant game designs ever. The fun factor was undeniable, and it had replay value because the game was randomly generated every time you played. The most memorable part of this game is the trading interface, a truly brilliant game design. Players needed resources of varying types, and would have to bid on them through an interface where players literally scrambled for resources-with the seller able to dance higher and higher on price as folks raced to buy. Brilliant and fun.

  • Advanced Strategic Confrontation: This was the rough translation from the Japanese name. The game was a Sega Genesis title released around 1990 that became the inspiration for the entire series of Panzer General games that kept Strategic Simulations going for years. This game was incredibly original, with a simple war game style that made war games accessible for the rest of us. All units had '10 hit points,' and could heal by sitting on friendly cities. Infantry captured cities, and tanks were for killing other units. They had artillery and air units, allowing the full 'rock, paper, scissors' strategy matrix. Though it wasn't released in the U.S., it was extremely successful in Japan, and still resides in my collection.

  • Star Control II: The only sequel on my top list. It took all of the arcade fun of the first game and combined it with a single-player RPG story that was both fun and, at times, hilarious. The replay value was mostly in the arcade mode, but the RPG side was deep enough that it was worth playing more than once to see what you might have missed. The only action RPG of its type, Star Control II has never been successfully imitated since. Note that the sequel, Star Control III, did not live up to its predecessors and effectively terminated the franchise.

  • EverQuest: I'd be remiss to leave this off my list, given how much of my life it has sucked out of me. The first true 3D MUD, this game still endures as the top massively multiplayer game of its genre. Filled with bugs, even after four years of constant development, Ever- Quest is still undeniably addictive (more so than alcohol or tobacco some might argue) and plain old fun. It is the perfect operating example of how powerful the concept of 'toy factor' is in a game-the base concept being the more toys players have to play with and sort through, the better. Of particular note regarding EverQuest is the incredible change the game has undergone, literally evolving to mimic the desires of the player base. EverQuest is perhaps the best example of a 'living game' we've ever seen.

  • Fallout: The original post-apocalyptic RPG, this masterwork helped maintain the vitality of the single-player RPG. Fallout had a deep storyline, yet didn't overwhelm the player with so many options that they got lost. It was long, but not so long players couldn't finish it in a reasonable timeframe (unlike the sequel). Add in a nice mixture of dark humor, and you have a game that is still top of the heap for single-player RPGs. Fallout spawned two sequels, and neither has lived up to the original, unfortunately.

What games have inspired you the most as a designer and why?

That's a difficult one-I'm inspired by literally every game I play. Though not every game is fun, nearly every game has some small spark that one can take away and apply to a good design. However, there have been a few that I could say were truly inspiring.

  • Diablo: The simplicity of the game combined with the idea of there always being more and better toys to get made this game amazingly addictive. The random nature of the design made replayability limitless, and caused the game's addictive nature to be only more powerful as there was always a bigger, better toy you could get. This game significantly influenced the way I have approached design elements on subsequent titles-even for non- RPGs. Most notably, it made me aware of the value of world/item generation systems in extending the replayability of a game.

  • Doom: The original modern FPS, Doom showed us all that a game needed smooth and fun gameplay far more than it needed elaborate back story or beautiful graphics. Doom was actually pretty ugly, graphics-wise, but the gameplay was so fun and the game so cohesive that it set in motion an entire new genre for modern gaming. Doom likewise showed me the import of maintaining the illusion. The game is seamless and stays totally within itself, never breaking the illusion with clunky interface, bad audio effects, or buggy gameplay.

  • Eastern Front: The original hardcore war game for videogame systems (Atari 400/800), this game was Chris Crawford's first major work and still is regarded as a landmark title. With clever and robust AI, Eastern Front is what inspired me directly to seek out videogames as a possible career path.

  • Star Fleet Battles: This is the gargantuan boardgame that expands, and is inspired by, the original Star Trek TV series. Star Fleet Battles (SFB) was the first game I helped work on professionally, and it taught me several important lessons about game design-not the least of which is that players know just as much as designers, and they are a very valuable resource. I spent several years working with the SFB design team (for no pay) helping design and write for them. That helped springboard me to my career, and inspired me directly to seek out design as a path.

What are you most proud of in your career?

Honestly, I think I'm proudest of the fact that I've never shipped an unsuccessful title. Every title I've been responsible for has made money and met or exceeded sales expectations. Though I've been blessed to work with some amazingly talented programmers, artists, designers, writers, and marketers-without my contributions these products may well not have been as successful as they were. My strongest suit is as a leader, using my design skills and sensibilities in combination with my ability to help guide others to successfully lead design and programming teams to deliver their absolute best.

What words of advice would you give to an aspiring designer today?

I would urge any prospective designer to become a complete package. It is not adequate to merely learn how to generate good designs; a skilled designer must also know how to communicate those ideas to others both in written and verbal form. A good designer must also be able to communicate concepts through visual tools, allowing the viewer to see what is in the designer's head. Likewise, interpersonal skills are also key, as a designer must sometimes negotiate for resources and/or for the ability to take a product in new directions when that designer isn't also the company CEO.

I will note that the theme of this book-and how it approaches game design-very much mirrors my own beliefs. I strongly support the idea of paper design prior to electronic implementation. Playtest your ideas thoroughly long before a coder codes. Use prototyping whenever possible to avoid inefficiencies that may end up costing you features later when time and money limit the scope of your project.

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Ticking clock

Many electronic games allow maps to be set up where a weak defender must fend off a strong attacker. The defender's objective is to hold out for a set amount of time. The attacker's objective is to kill all defenders before time runs out. The second mission in StarCraft works this way. In it you must build a small human base and hold out for 30 minutes before being overrun by a horde of attacking Zerg.

The ticking clock is a staple in mission-based games including Homeworld, WarCraft, and Command & Conquer. The model is also used in turn- based military boardgames such as Panzer General. Here the ticking clock victory condition is measured in a set number of turns versus a set amount of time. The weaker defender must hold out for 30 turns.

The multiplayer mode in the RTS game Age of Empires lets players choose to start the ticking clock as a victory condition on their own. They start it if they choose to build an expensive building called a 'wonder of the world.' When one player builds a wonder, all opponents see the ticking clock start on their screen. The player must now defend his wonder from being destroyed by all other players. If he can hold out until time runs out, then he wins the game. In this case the ticking clock is a victory condition chosen strategically by a player. It is balanced into the game to enable richer methods of play.

Protection

This is a variant on the ticking clock, and it can be equally dramatic. In this model one side tries to protect something (such as a princess, magic orb, secret document, etc.) and the other side tries to capture it. If the defenders protect or sneak the thing to safety, they win. If the attackers capture the thing, they win. Many games include missions that work like this. One example is the beach invasion map in the WWII-based game, Return to Castle Wolfenstein. On this map, the Allies' objective is to storm a beach held by the Axis. Then they must penetrate a seawall, infiltrate the base, and steal several top-secret documents. The Axis objective is to protect these things and keep the Allies from completing their goals.

Combination

It's also possible to combine ticking clock and protection devices. Take, for example, multiplayer assault maps in the FPS game Unreal Tournament. These maps have a ticking clock (usually four to seven minutes long), as well as objectives that need to be protected. The attackers' goal is to reach the headquarters, steal the code, or blow up the bridge. They try to do this as quickly as possible, while the defenders protect the objectives for as long as possible, or until the ticking clock runs out. When the goal has been met, the time to beat is displayed. The two teams then switch roles. They play the same map, but the team who was just attacking is now defending. The new attackers try to beat the time set by their opponents in the previous round. This type of game can be extremely exciting because of its clear objectives and dramatic use of time.

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Figure 9.9: NetRunner-corporation cards versus runner cards

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Figure 9.10: Illuminati Deluxe

Exercise 9.9: Asymmetrical Objectives

start example

Take the original game prototype you've developed and create a variant with asymmetrical objectives. If your game is a single-player game, add a choice of objectives. Describe what happens to the gameplay when you test the game with these changes.

end example

Individual objectives

In the classic boardgame Illuminati, the designers use asymmetrical objectives in a novel way. It's a game of politics, diplomacy, and sabotage in which opponents vie for control of societal groups such as the Mafia, the C.I.A., the 'Boy Sprouts,' Trekkies, and convenience stores. Each player can play for a shared objective-to control twelve groups-or go for their own individual objective. For instance, the individual objective for the Illuminati group is to destroy any eight groups. The individual objective for another is to control five 'weird' groups. Players must watch to ensure that no one gets the shared objective while also battling and negotiating to ensure that other players cannot achieve their individual objectives. The differing objectives create an environment of shaky alliances and mutual distrust. The game is balanced so that, to win, players must cooperate with one another in some instances, and betray one another in others. The winner almost always succeeds by meeting her individual objective as opposed to meeting the shared objective.

The previous models are only a few ways to think about asymmetrical objectives in games. Like many concepts in game design, there are other ways to go about it-some of which can be found in existing games and some of which have yet to be invented.

Complete asymmetry

Scotland Yard is a popular boardgame in which just about everything is asymmetrical. In this exciting boardgame, one player takes on a group of opposing players who work as a team. This player is the fugitive, Mr. X, and the other players are a team of Scotland Yard detectives trying to track him down. To make this contest fair, the designers at Ravensburger balanced the system so that Mr. X has the ability to hide. He also has unlimited subway, bus, and taxi tickets (i.e., resources) from which to choose. Mr. X moves around London invisibly but must surface every four or five turns according to a turn schedule. The detectives use information about where Mr. X was last sighted and work in coordination to try to surround him and cut off potential lines of escape. The detectives have a set number of movement tickets. If one of them runs out of a type of ticket, he can't use that mode of transportation anymore. Mr. X's objective is to evade capture for 24 turns. Thedetectives' objective is simply to catch Mr. X at any time. Essentially, the following are balanced against one another: Mr. X with unlimited resources and the ability to hide, versus four or more detectives with limited resources and the ability to work in coordination. The game variables are tuned so that over the course of a whole game each side has an equal chance of winning.

In the symmetrical and asymmetrical multiplayer models we've just looked at, the most important balance to work out is between the various players. Because most models of multiplayer interaction employ other players as the basis of the game conflict, the question of balance often comes down to a question of how resources and powers are distributed to each party at the start of the game.

In single-player games, however, conflict is usually provided by the game system-either in the form of obstacles, puzzles, or AI opponents, which we discuss on page 251. As with the multiplayer models, single-player games can also employ symmetrical or asymmetrical forms of play.

Balancing for skill

Balancing for skill involves matching the level of challenge provided by the game system to the skill level of the user. The challenge with this is that every user has a different skill level.

For some games, it's practical to simply offer multiple skill levels. For instance, the original Civilization offers five skill levels: chieftain, warlord, prince, king, and emperor. Each of these levels is progressively more challenging to play. The difference between the skill levels in this system is simply a different balance of numbers in the system variables (see Figure 9.11).

When you play Civilization at the easy level, chieftain, you start with cash reserves of 50, and when you play at the emperor level, you start with cash reserves of 0. At chieftain, the computer opponents attack at .25 strength, whereas at emperor their strength is multiplied by 1.25. Figure 9.11 on the next page shows a chart of the system variables for each Civilization skill level.

Exercise 9.10: Skill Levels

start example

Does your original game have skill levels? If so describe how they work and the method you used to balance them. If not, why not? Can you add skill levels and how would they affect the gameplay?

end example

What if it is not practical to offer multiple skill levels for your game? Perhaps your design is not as dependent on starting variables as the Civilization example. In this case, your best bet is to balance the system variables against the median skill level of your target players.

Balancing for the median skill level

Balancing for the median skill level requires extensive playtesting with players from your target audience across the range of ability levels-from novice to hardcore gamers.

A good way to find the proper ability levels is to first set the high water mark of difficulty by testing with hardcore gamers.[3] Next, set the low water mark by testing with novices and progressively adjusting the difficulty level downwards.

click to expand
Figure 9.11: Civilization difficulty levels

Once you have these boundaries established, you can balance the system variables to be in the median between these two marks. In games that are structured in progressive levels of play, which is most single-player videogames, you can incrementally increase the difficulty level for the player as you move from level to level in the game. Of course, each level will have to be balanced individually.

Balancing dynamically

In some types of games it's possible to program the system to adjust to the ability level of the players as they play. Take Tetris, for example. In this famous game, different-shaped blocks fall down- ward from the top of the screen. The player rotates the blocks and moves them left or right as they fall in order to attempt to fit them together at the bottom. If the player fits pieces together to fill a row completely across, that row disappears and points are scored. When the game starts, the blocks fall slowly, so it's fairly easy for the player to fit them together at the bottom. But as the score increases, so does the speed at which the blocks fall. The system is balanced so that the difficulty increases automatically as the player's ability increases. In this case, difficulty is directly related to the variable of speed.

Single-player racing games such as Gran Turismo 3, Project Gotham Racing, and Mario Kart 64 have a self-balancing mechanism. In these games, when a race starts, the computer opponents (i.e., the other cars) accelerate up to their maximum speed. This speed is slightly slower than the maximum speed achievable by a human player if he drives perfectly. The computer opponents remain at max speed as long as the human is close or leading the race-meaning the pack will be tight. When the human crashes his car, the rules for the computer opponents change. They slow down to a reduced speed so that the human can catch up.

Once the human player closes in on the computer opponents, they accelerate back to their maximum speed. The human players may be unaware that this is going on. The ideal is for the human players to feel that they are successful because of their own abilities, but at the same time, keep the game balanced so that novice players aren't shut out from the possibility of winning.

Balancing computer-controlled characters

A problem with designing computer characters is that they must seem to be human and make mistakes. Otherwise a computer-controlled racecar could whiz through a track at maximum speed without crashing; a computer-controlled rifleman could hit an opponent between the eyes with every shot. This would clearly be no fun for a human player. Designers solve this problem by designing a character to act within a range of possibilities. Here's how the flying saucers work in Asteroids as explained by the programmer, Ed Logg: 'Sluggo [the big saucer] fires at random. Mr. Bill [the little saucer] aims. Mr. Bill knows where you are, and he knows what direction you're moving in. He takes this information and picks a window bounded a few degrees on each side of you, and then shoots randomly inside of that. For this reason, you should never move straight at him. It makes you bigger relative to him. [Also] the higher your score the more accurate Mr. Bill becomes. When your score reaches 35,000, he narrows down his firing window and increases his chances of hitting you.'[4]

click to expand
Figure 9.12: Balancing for the median skill level

click to expand
Figure 9.13: Tetris for Game Boy

click to expand
Figure 9.14: MotoGP and Road Rash

MotoGP © 1998 2000 Namco Ltd., All Rights Reserved. Courtesy of Namco Holding Corp.

In this example the saucer aims randomly within a few degrees of the player. This provides a variable that can be tuned to balance the game. If the number of degrees is increased then the saucer is more likely to miss and the game is easier. If the number is decreased then the saucer is less likely to miss and the game is harder. The result is a balanced, challenging, but not impossible, computer opponent.

Programmers have created many clever ways of coding their computer-controlled characters. In fact, there are many books just about programming game AI. What's important for you as a designer is not how the characters are coded but that they can be tuned to provide a balanced and satisfying experience.

[1]Ernest Adams, 'A Symmetry Lesson,'Gamasutra.com.

[2]Ibid.

[3]Tim Ryan, 'Beginning Level Design Part 2: Rules to Design by and Parting Advice,' Gamasutra.com.

[4]Own, 'Invasion of the Asteroids.'



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Game Design Workshop. Designing, Prototyping, and Playtesting Games
Game Design Workshop: Designing, Prototyping, & Playtesting Games (Gama Network Series)
ISBN: 1578202221
EAN: 2147483647
Year: 2003
Pages: 162

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