Theory: Dependency in Cooperative Games

Cooperative games exist on a sliding scale based on how players interact with each other. Some feature high levels of dependency: players rely heavily on each other to carry out their respective tasks. Low-dependency games, on the other hand, allow players to progress independently. Recognizing where a design falls on the dependency spectrum is vital, because it has an enormous effect on the player experience.

In high-dependency games, player 1’s ability to perform in-game actions is gated by player 2’s choices. American football has many examples: the wide receiver simply cannot catch a ball the quarterback throws too inaccurately, and a running back stops at the line of scrimmage if the offensive linemen do not make a hole. Video game healers often fall into this category as well, unable to raise health bars when the rest of the team has gotten themselves killed.

High dependency means that if the rest of the team plays badly, or according to a different gameplan, player 1 cannot act. This makes players extremely aware of each other, and can create a very strong team experience. Clockwork moves that enable successive players to act at their best are both intrinsically satisfying and impressive to watch. When this kind of game is going well, the positive feedback is extremely strong.

On the other hand, when things get off the rails high dependency games turn nasty. Successful play is like an assembly line, and when widgets stop coming it’s easy to identify where the issue arose. The center snapped correctly, the quarterback threw accurately, and then the wide receiver was supposed to catch it and run—but that last step was missed. Since center and quarterback did things right, it must be the wide receiver’s fault. If the team is fractious, or team members enjoy the anonymity of online play, recrimination is apt to follow.

Low dependency play avoids turning player 2 into a gate for player 1. Pandemic’s Researcher can always cure diseases regardless of what the Medic is doing. Team Warmachine tournaments pair off members of opposing squads, such that teammates cannot help or hinder a game in progress.

It’s much easier to keep team dynamics positive in low dependency games. Everyone gets to do their thing, whether or not others are succeeding. Assuming “their thing” is fun, the game can be satisfying even if the rest of the group is having trouble.

Yet, low dependency makes it quite a bit more difficult to create a team dynamic in the first place. If everyone can act independently, it is easy to ignore one’s teammates. The game can devolve into loosely connected solo games, or the most skilled player dispensing with cooperation in an effort to carry the entire game.

Neither high nor low dependency is inherently better. Both dynamics provide value, and the weaknesses of each can be designed around. It is possible to shift between them, or to incorporate elements of both, adding just enough dependency to a game to keep a team together while providing independence to cool tensions.

The key for designers is to position their game on this spectrum consciously. Increasing dependency risks increasing toxicity; decreasing it can undermine cooperation. Knowing that, one can design around it.


25th Hour Projects: The Game of Waltzing

Games about movement are everywhere: most wargames, vehicle racing games, arguably even games like Pandemic. Their success makes it all the more surprising that we haven’t made more games about other kinds of movement. For example, wouldn’t a game about waltzing be neat?

Think about it. You have to act in coordination with your partner, but you’re not allowed to talk (we’re in a competition, after all!). Right there, the theme provides a strong justification for a co-op without the risk of a dominant player.

Furthermore, the actions being taken are tense moment-to-moment. Each step has to be perfect, or disaster could strike. As in Pandemic, no one can afford a wasted move.

Dance is a universal human activity, yet–like so many universal human activities–games have yet to explore it in any serious way. I hope we see that rectified soon. Maybe I’ve even got an iron in the fire along these lines . . . .


Theory: Providing Zero-Level Heuristics

Suppose a brand-new player understands the rules to your game, and further has a general grasp of what each of the available options is meant to accomplish. The next thing that player needs is a zero-level heuristic: a rule of thumb that guides the new player’s tactical decision-making. Providing zero-level heuristics makes people’s first games more enjoyable, which tends to ensure that they’ll come back for a second.

We’ve talked about this issue before in the context of chess. It’s not hard to understand the rules of chess, but it’s very difficult for a new player to figure out what moves might be good. “Capture the opponent’s king”—yes, but how? It’s not easy to envision how one might get there from chess’ neutral starting point, and many people won’t grind through the frustrating initial games required to develop basic strategies.

Luckily, there are a number of ways to provide zero-level heuristics. Here are a couple of options; I’m sure there are more.

1. Player powers

Making players better at doing things tends to suggest that they should do those things, which gives them a basic goal to get them through their first few turns. Pandemic’s medic is a great example. As soon as someone gets the medic role, they know they should be treating diseases; that simple guideline will be enough to carry them until they’re in the swing of things and able to engage with the game’s decision-making more fully.

The recently-released starter set for Warhammer 40,000’s Space Marines uses a similar technique. It comes with a special rule for the pieces within; roughly speaking, the leader can make some of the other models stand their ground and fire twice in one turn. New players will naturally want to take advantage of that rule—and while doing so, they’ll discover that their troops are very good shots! That knowledge will help them plan their turns going forward.

2. Graphic design

Imagine a board laid out in an elaborate series of fractal spirals. Should you go left? Right? Who knows! The board twists in on itself, again and again, defying any attempt to parse the game just by looking at it.

By contrast, imagine a board that’s a straight line with “start” on one side. Everyone knows what to do with that board: get to the other side. Long experience with other games will tell new players that any move that gets them closer to the opposite end is probably good. Relying on that intuition will get them underway.

(Implicitly, this means that you probably shouldn’t create straight-line boards with “start” on one side when the goal is not to reach the other end.)

Obviously, not every game can have a linear board. However, many can have “juice” that tells new players what to do. Sparkles when they make a good move; bright, strong lines pointing toward one of the actions on the play aids; color-coded actions with the most basic and important actions being the same color as the goal on the board. Just about any game can use its art to communicate what a new player should focus on.

3. Give a small number of very good options

By and large players want more options. There are occasions when it’s appropriate to give them fewer, however, and the period in which you need to give new players zero-level heuristics is one of them. Allowing a player only a couple of choices that all lead to obvious gains ensures that they’ll begin the game by seeing something they can do to progress.

Advanced Civilization executes this technique brilliantly. There’s a lot going on in Advanced Civ, but in the first turn all the player can do is expand to a single new space. Both of those spaces will then produce an additional figure for the player to work with. Expansion is central to the game, and so new players get to take a turn (a) figuring out how to do it and (b) discovering its power; with that knowledge they can focus on expanding for the next several turns and do just fine.

Taken by the hand

Zero-level heuristics don’t take over for new players. Rather, they help make first games entertaining by providing context and the information necessary to evaluate options. Give thought to how you can provide zero-level heuristics as you work on the new player experience; those just picking up your game will thank you for it.

Theory: Rules for Player Powers

After hammering away at Lines of Questioning for a while, I feel that the latest variant is a great foundation for a “basic game.” However, it’s also incredibly difficult; saying that playtest victories have been elusive is somewhat like saying that one doesn’t often see a unicorn.

My thinking at the moment is that the core gameplay mechanics are solid, and that the difficulty issue can be addressed with role or power cards that give the player a little boost. Legal analysis teaches that a free-ranging quest for good ideas is less effective than following reliable guidelines, so I thought that as a first step I should try to create those guidelines. Here’s what I’ve come up with.

Player powers in cooperative games (which can include solo games for our purposes here) come in two types: weighting and unique. Both serve to make the game easier, and hopefully more fun as well. However, they accomplish these goals in very different ways.

Weighting powers make the player better at a game action everyone can take. The player might pay a lower cost for the action, or get a bigger payoff, or be able to take it when other players cannot. However it happens, the power weights the player’s choice; it puts something heavy on one side of the scale that balances the options.

Perhaps the quintessential weighting power is the Medic role in Pandemic. The Medic can do all the things the other players can do, but is the best in the game at treating sick people. Since treating sick people is absolutely necessary to win, and the Medic does it better than everyone else, the Medic player’s evaluation of how he should spend his turn is always going to be tilted in that direction.

Unique powers, by contrast, enable the player to do something outside the normal game rules. Instead of making a choice more appealing, as in the case of a weighting power, it adds a whole new option. Players without the power cannot replicate it, even inefficiently. Recent implementations of the idea include Forbidden Desert’s Climber, who cannot be buried under the game’s shifting sands, and Space Hulk: Death Angel’s squad-specific action cards.

Admittedly, the distinction between these categories is not always a bright line. Having a unique power does tend to weight one’s choices; the Climber can move to the same squares as every other Forbidden Desert character, but her additional safety can have a substantial effect on the choice of destination. Similarly, weighting powers can be considered “unique” insofar as they enable players to break the game’s normal rules.

I nevertheless feel that it’s useful to think in terms of powers as coming in two flavors, because they work out somewhat differently in play. Weighting and unique powers produce different behaviors in players and can be used for different purposes.

Weighting powers have subtle, but important, impacts. First, they provide guidance to the player. By making one choice more appealing, weighting powers signal to the player that that is a good choice and he should go in that direction as often as possible.

Think back to Pandemic. If you take a group of people who have never played the game and give them each a role, the players will naturally gravitate toward whatever their roles tell them they’re good at. The Medic will start treating the sick; the Researcher will try to get cards to the Scientist; the Operations Expert will build research stations. All of those are useful contributions, and so that inexperienced group will make progress in the game.

Compare that to what would happen if Pandemic had no role cards. Should everyone treat the sick? Maybe the best strategy is for everyone to build research stations all at once, and completely ignore the cards? Who knows! New players would be completely at sea, and might suffer through many frustrating games while they figured out a reasonable distribution of labor.

That thought experiment points toward another benefit of weighting powers: they are an easy source of player satisfaction. It feels good to treat sick people as a Medic, because each treatment is a little chance to be top dog. No one else can treat people like the Medic can.

As the game goes on those opportunities can even build into something especially satisfying, a reputation for competence and accomplishment. When the table comes to rely on the Medic, trusting him to keep them in the game while everyone else does their behind-the-scenes work, it gives a taste of what it’s like to achieve a position of responsibility in the real world.

By contrast, unique powers offer neither of those things. They do not generally help players decide what to do; if anything, they make in-game decisions more complex. In Space Hulk: Death Angel the purple squad has the ability to move the evil aliens around. It’s difficult to say whether and when that’s better than just attacking them; the choice is highly context-driven, and nothing about the ability itself signals which way the player should go.

Nor are unique powers always going to be wells of player satisfaction. Frequently they just create agita as players struggle to decide whether they should use a power now, or save it for later, or use the power in a different way. We have all seen people frustrated at the end of a game because they were so afraid of wasting their Cool Thing that they never actually did it.

Unique powers are nevertheless still valuable despite those weaknesses because they are an effective route to new decisions and different play experiences. As an example, take another look at Forbidden Desert. Most of Forbidden Desert’s players operate in an environment characterized by water scarcity. The Water Carrier, on the other hand, can have as much as she pleases if she’s willing to spend the time to dig a well; for her the game is all about opportunity costs. Having a unique power fundamentally changes the experience for that one player, which helps keep the game fresh and interesting.

These, then, are the rules I’ll be using as I design player powers for Lines of Questioning:

First, follow the rules here for when player powers are useful, and in what amounts.

Use a weighted power when (a) the power should help players, especially new players, decide how to approach the game; and/or (b) the power is meant to add satisfaction to the game experience.

Use a unique power when (a) the goal is to create a new set of decisions; and (b) the power will not frustrate players by being difficult to use correctly.

On Monday I’ll be back with first-draft ideas.

The Case Study: Player Powers, Take Two

Cooperative games often give each player a unique power: Pandemic makes one player a scientist and another a medic, while Forbidden Desert has one player be good at carrying water while another can dig quickly. Yet, it isn’t necessary for a co-op to do so; Space Alert is a great game, and all of its players are on equal footing. I’ve been interested in bringing unique player abilities into Over the Next Dune, and have even put forward some untested ideas, but before sinking a lot of time into it I want to figure out with confidence whether OtND is in the category of games that benefit from such abilities or the category that doesn’t.

When would one want to add unique player powers to a game? I’ve come up with a couple of possibilities:

1. The game benefits from a certain amount of something, but no more. Pandemic would be easy if everybody had the medic’s ability to cure lots of people in a turn. However, letting one person do that is just enough to keep the players above water when the cards flip the wrong way and disease suddenly spreads all over. A single medic serves as a safety valve without making the game trivial.

2. The unique abilities provide very different game experiences. Playing a Dwarf Trollslayer in Warhammer Quest has little in common with playing a Grey Wizard. Providing such distinctive experiences adds a lot of replayability, since getting tired of one of them doesn’t mean you’re tired of the game as a whole.

3. The unique abilities create new, interesting decisions. Playing the water carrier in Forbidden Desert is neat because in addition to the game’s usual decisions you have to decide how important it is to stay close to oases. Figuring out when it’s safe to go help the team and when you should to stay behind collecting water is tricky. The unique power is valuable in part because it brings that interesting decision to the table.

Looking at that list, I’m struck by the fact that it’s mostly about the powers rather than the game. Do the abilities provide different experiences? Do they create new decisions? It depends on what the abilities are!

We could come at the problem from the other direction. When would one not want unique player powers in a game?

1. Giving players unique capabilities would undermine the game’s mechanics. Diplomacy is a classic game of cooperation (and competition). It’s a wargame where the players’ strengths start out relatively even, so to make progress you have to cut deals. If the players had special abilities they could rely on it might make negotiation less important–and the negotiation is the reason to play.

2. The game is at a complexity limit. Space Alert is played in real-time on a 10-minute clock. Players make mistakes and overlook things, even without having to track the effects of special powers. If people were also trying to manage unique abilities the game could tip from “hilarious barely-controlled chaos” into “impossible and frustrating.”

Over the Next Dune certainly isn’t so complicated that it can’t bear the weight of unique abilities. I’m less certain whether player powers would undermine the game’s central challenge of tricking the searchers. On the one hand, the more tools the players have the less likely they are to take the risk of getting close to searchers to pull them around. On the other hand, it seems like abilities could be created that would increase rather than detract from engagement with the searcher-tricking mechanic.

The best way to resolve that uncertainty is with some testing. How about this as a starting point:

Pop a Tire: If this player token is adjacent to one or more searchers at the start of the Sneak Phase, that searcher is affected by terrain during the next Search Phase. (Any time during the next Search Phase that searcher’s movement would cause it to enter one or more squares with terrain in them, the searcher must expend two squares of movement instead of one. If it does not have enough movement remaining to expend two squares of movement, it stops moving.)

My thought is that this creates a new decision (whether and when to slow down a searcher) and a potentially different game experience (seeking out searchers instead of avoiding them), without adding complexity (players will already know the terrain rules) or undermining the central mechanic (since it increases rather than decreases the mechanic’s use during the game). I also like that, as noted in the first iteration of this ability, it doesn’t empower one player; rather, it helps a player assist the others.

That’s one power, but there can be five players in a game of Over the Next Dune. I’ll be back with more on Monday.

Theory & The Case Study: Gates in Over the Next Dune

I’ve been considering whether to try out gated player abilities in Over the Next Dune. Gating player capabilities would be a substantial change, and unusual for a cooperative game. On the other hand, gates are a commonly-used, proven mechanic. It’s not a trivial decision.

Let’s start at (what I think is) the beginning. Why would one ever use a gate, instead of just letting players deploy their capabilities whenever they want? I can see two reasons:

1. The gate leads to interesting decisions. Mark Rosewater likes to say that “restrictions breed creativity.” Limiting the player’s access to a capability forces the player to think about when to use it, and to find alternative solutions when the capability isn’t available or shouldn’t be employed.

As a quick example, think about Barrier in League of Legends: a protective shield that isn’t available for a few minutes after being used. Since access to the Barrier is limited, players have to make tough decisions about precisely when it will do the most good. They also have to find ways to conserve the Barrier for those key moments, and to protect themselves when the Barrier is “on cooldown.” If players could just throw up the Barrier all the time, those decisions would be lost–and no other decisions would appear to replace them.

2. The gate prevents an ability from dominating gameplay. In some ways this is the inverse of the previous rule: the gate is in place because unlimited use of a player ability makes the game less interesting. RPGs often use gates in this way; powerful abilities would make the early game trivial, so players can’t access them until later.

(There’s also a third reason–to help monetize the game. However, that opens up a can of worms that I’m not looking to address right now.)

Those both seem like good reasons to include gates. Yet, they aren’t universal in cooperative games. Pandemic‘s Scientist doesn’t need to do anything to be able to cure a disease with four cards instead of five; that ability is always “on.” Shadows Over Camelot‘s Sir Bedivere can trade cards in for new ones without earning the privilege. Clearly, gates aren’t for every power or every game.

What considerations, then, militate against gating player powers? Ironically, I find it much easier to think of why a designer would want to limit powers than why the designer wouldn’t. Perhaps that says something about me. 🙂 Here’s what I’ve come up with:

1. The game is unplayable when the ability is not available. Most RPGs don’t limit your capacity to walk around. In fact, I’m not aware of any at all that do. That’s not surprising, because if the player can’t move around the world in an RPG the player can’t do anything at all. Limiting walking would tend to destroy people’s ability to play the game.

2. The game needs something, and the ability provides it best when it is constantly available. League of Legends needs a way to ensure that games move toward their conclusions. A big part of ending a game of League is damage output; players and teams need damage to destroy the opposing team’s defenses and ultimately the enemy base. Thus, the game needs to ensure that teams have reliable access to damage output. If no team can damage objectives, the game cannot progress (setting aside really grindy strategies like letting minions do all the pushing–let’s not go down this road).

League’s need for guaranteed damage is met by “auto-attacks.” Every character can punch, swing a sword, fire arrows, or has some other freely available mechanism for inflicting damage. Since they’re costless, auto-attacks guarantee that the game cannot stall completely. Regardless of the team composition or overall situation, both teams have the theoretical ability to bring down objectives and end the game.

3. You want to encourage a behavior. If players should be doing something in a game, designers can incentivize it by letting players do it no strings attached. Ikaruga, for example, is a “bullet hell” game in which the player(s) can switch colors to absorb enemy fire. The color-switching mechanic made the game an instant classic. Having no limits on switching colors was a good design move, because it encouraged players to try the mechanic out early (desirable because color-switching was the game’s innovative feature) and to do it often thereafter (important because it helped players progress and kept them hooked).

So, two reasons to use gates and three not to. What do they mean for OtND?

To date players have three capabilities in the game: moving, tricking searchers, and rescuing other players. Moving should not be gated. The game is unplayable if players can’t get around the board.

Tricking searchers also should not be gated. It is, at least arguably, the most interesting aspect of the game. Keeping it freely available encourages players to interact with this important mechanic.

Rescuing is already gated by the need for several players to work together. That proved necessary to stop rescuing from dominating gameplay. However, the current limitations appear sufficient; I don’t think more are needed.

What about additional player abilities, then? Things like Pandemic’s Scientist and Shadows’ Sir Bedivere, that are outside the core rules of the game? Do they need to be gated? Should they exist in OtND at all? Let’s take that up next time.

Theory: Simulation and Puzzle Pure Co-Ops

It’s an article of faith that a great opponent makes a game more fun. A good pure co-op game, then, needs a good AI foe to challenge the players. Designing that opponent requires, first and foremost, deciding what kind of co-op you’re creating: a stand-in or a puzzle. Mashing elements from both types together leads to trouble.

A stand-in challenges the players by imitating a living opponent. It tries to do what a human would do in a given situation. In essence, it simulates the experience of having a human sitting across the table (or on the other side of the internet connection) playing against you.

A puzzle challenges the players by presenting a problem for them to solve. It is not concerned with doing as a real person would do; its only goal is to provide an interesting dilemma, and it acts in whatever way the designer thinks will best achieve that. Puzzles may (should?) have a theme, and they may be good simulations of that theme, but they aren’t trying to simulate an opposing player.

Which category a game falls into has a huge impact on what kind of AI is appropriate. Stand-in AIs need capacities that puzzle AIs don’t. A human will respond to his or her opponent’s actions; to feel “real,” the stand-in needs to be able to do the same. It has to be able to find out what the players are doing, determine what an appropriate response might be, and implement that response.

Puzzles, by contrast, don’t have to care what the players are doing. In fact, they don’t have to do any specific thing so long as they’re interesting. The central question is what the game needs, not how a person would behave, and the AI needs only those capabilities relevant to the game’s particular answer.

Either choice can lead to a great game. Pandemic and Forbidden Desert, for example, are both great puzzles. The diseases to cure in Pandemic and the sandstorm to dig through in Forbidden Desert don’t act like human opponents–but why would they? Diseases and sandstorms aren’t sapient, and it would be weird if they could respond to the players’ actions. Instead they operate in ways that are both thematic for the natural forces they represent and interesting in play. For puzzles, that’s the gold standard.

As an example of a great stand-in I always go back to the Reaper Bot and Zeus Bot for the original Quake. (Wow. I’ve been playing FPS games for a long time.) At a time when a lot of people were on dial-up and internet play with other humans was a lag-filled affair, the Reaper and Zeus Bots were striking for their ability to navigate without bumping into walls, good aim, and consistent connection. Many real players, fighting against 300-500ms pings, couldn’t offer those things. The bots out-humaned the humans!

Designers run into trouble, however, when they mix the two categories. One sees this a lot with “cheating” computer game AIs (which are usually intended for solo play rather than co-op, but the issues involved are comparable). They look like stand-ins but are actually puzzles, and as a result they often end up being unsatisfactory.

For example, players often express frustration with the AI in the Civilization series of games. Civ’s AI promises stand-ins; the player controls one civilization and the others are guided by an AI that has each civilization pursue its own ends–just like they would if humans were guiding them. The goal is to beat the other civilizations, eliminating or outscoring each as though they were separately controlled by human players. The AI-driven civilizations sometimes cooperate and sometimes attack each other, imitating what humans do. It looks like a stand-in, it quacks like a stand-in . . .

. . . but it’s not a stand-in, and at least anecdotally it ends up irking many players as a result. Civ’s AI doesn’t get much smarter as the difficulty level goes up; it just gets more and more resources, far outstripping what the human player receives. Those resources enable the AI to challenge a skilled player, but they undermine the simulation; no human can do the things a high-difficulty AI can do. Ultimately the game becomes a puzzle in which the player must find optimal moves that will allow him or her to keep up with the AIs’ lead in technology and production. Players choose a higher difficulty level looking for a simulation testing their diplomatic ability and battlefield tactics, instead find an optimization problem testing their command of the math behind the game, and walk away aggravated.

(To be fair, some players greatly enjoy the higher difficulty levels. However, they’re usually knowledgeable about the game, know they’re in for an optimization problem, and are specifically seeking that experience.)

Civilization demonstrates–-has in fact been demonstrating for years–-that a really tasty apple is not a substitute for an orange. When designing a pure co-op, follow in the mold of Pandemic, Forbidden Island, and Quake’s excellent bots by figuring out whether you need a puzzle or a stand-in and then delivering fully on that experience. Slipping elements of one into the other is apt to confuse the game’s message and frustrate players.