Encouraging Cooperative Behavior in Co-Op Gameplay
There’s a difference between having two players in a game space, and having truly cooperative gameplay. The Splinter Cell series has become well-known for the latter; missions that really reward cooperation between two agents.
Players respond to collective agency. When they feel like they’re both making an impact on the situation, they want to hold up their end of the bargain.
Players will work together to optimize their output. This can be a challenge, because two agents can interact with a system in unpredictable ways, and really be more effective than one player. Or, they can screw up.
Twice as many players = way more that twice the chance of detection. Creating meaningful stealth opportunities when you need to conceal two agents is much harder than concealing one. But, players can use their knowledge of the game to improve their odds, making it an interesting challenge.
Allow players to express themselves through gameplay. Let them develop their strategies, make plans, and take risks. Make both players feel smart and effective.
Players dislike forced cooperation, but enjoy meaningful cooperation.
Cooperative dynamics are how the mechanics influence the player’s inputs, and the outputs they receive.
Many mechanics were introduced.
- Gating/tethering: The most basic mechanic. No player can proceed unless all players are present. It’s usually pretty obvious.
- Exotic challenges: One player has a unique perspective/controls, and other players need to cover them. An example is manning the minigun in Left 4 Dead: you’re more powerful, but you can only aim in a 180 degree arc, and you can’t melee to defend yourself.
- Punitive systems: One player is trapped, and requires rescue/help from another player. Too much of this can feel like punishing the player just for trying to play the game their own way, but it can also create cool situations where players can keep the team alive even after a normal failure condition. These systems can be a little weak at creating coop play, because they’re avoidable by skilled play. Don’t let a smoker get you, and you never need to do the smoker rescue mechanics.
- Buffing systems: One player makes another more powerful, usually sacrificing their own effectiveness to do it. This can create cool coop gameplay, but you can’t rely on it too much, because players can always choose to just ignore it and fight on their own.
- Asymmetric abilities: Each character has special abilities and/or weaknesses, and you work better as a team. MMORPGs are a good example of this.
- Combined Actions: A situation requires different player skills at once. This is different from character skills; you’re not limited by your character, but you need to specialize briefly. The classic example is the Warthog: one player driving, one player shooting.
- Survival/Attrition: The game continues as long as one player is alive. Death is permanent (at least until the next checkpoint), so defending each other to ensure that at least one person get through is a victory.
Overall, high-level plot isn’t as important as character events. Players don’t talk about how they stole data and transferred it to the U.S., but they do talk about how they totally elbowed that guy just in time for you to get a clear shot on them and it was awesome.
Don’t put a lot of effort into prescriptive systems, like needing to hoist a friend over a wall. Players understand these things. They know you need these coop points. Trying to mask these points as natural parts of the gameplay will just result in players getting confused about what they need to do.
Give players the tools they need to support each other, and be reliant on each other.
Focus on readability in your gameplay mechanics, path, stealth, etc. Two players in the environment creates lots of sensory, system, and social noise. Make it all easy to read.
Trust that groups of players will naturally find improvise their own solutions to hard problems.
Biofeedback in Gameplay
Valve did a cool panel on using biofeedback systems to gather data and/or control gameplay. Biofeedback means stuff like heart rate tracking, eye movements, and such. It should be the most natural form of input – you don’t need to think or do anything, you just need to be human and get into the game!
Exposing biofeedback data to players can create a feedback loop. They get nervous, and they see that they’re getting nervous, which makes them more nervous…etc.
Controls map player intent to the game.
Biofeedback maps player emotion to the game.
You get to factor in not just what the player is explicitly telling you, but also what they’re feeling about the game.
Emotion is a response to external events. It has a vector, with an intensity, and a direction (positive/negative emotion).
The biofeedback methods presented were:
- Heart rate: Cheap, easy to measure, but prone to errors due to movement, and delayed. It takes several seconds for your heart rate to change due to stimuli.
- Skin Conductance (SCL): Very cheap to measure, and short lag time, but the range differs between subjects, requiring evaluation and calibration.
- Facial Expressions: Great for getting an exact emotional response, and expression is usually instantaneous in response to stimulus. But measuring expressions generally can’t be done in real-time, is intrusive and expensive to record, and requires training to interpret.
- Eye Movements: Very good measure of exactly what the player is paying attention to, and for how long. It tracks player thought processes fairly well. However, it requires very expensive gear to track, and gaining data from eye movements requires later review and evaluation.
- EEGs: Measure the electrical potentials of the brain. You can get a good measure of arousal, and a general idea of what kind of thought the player is doing. But EEG setups are very expensive, very intrusive (a big metal thing on your head), and it’s difficult to really get clear data out of all the signals.
Valve showed three demos:
1) Left 4 Dead 2, with the director’s estimated tension level replaced with an actual, measured tension level from the player. Valve’s data showed that players had more fun, as the game reacted more naturally to them.
2) Alien Swarm. A stage was created where players would kill 100 enemies in 240 seconds. However, if they got nervous or agitated, the clock started ticking faster. They definitely saw a feedback loop – get nervous, the clock speeds up, which makes you more nervous.
3) Portal, with eye tracking to control the crosshairs. I was impressed by this one – the player’s gaze flicked rapidly from surface to surface, firing portals with pinpoint precision. This has the potential for perfect control in shooters, instantaneous reactions and perfect headshots. But is that desirable? It takes time to raise a gun, sight it, and fire. On the other hand, it seems wrong somehow to suggest that what we want is less accurate, less responsive controls than are possible.
Valve knows that biofeedback isn’t coming to the consumer level any time soon, but their research still served an important role. Is there an optimal arousal pattern, which leads to an optimal gameplay experience? Can we use biofeedback to make good gameplay become great?
Rise of the Power Creative – Cliff Bleszinski
Cliff’s talk on the power creative has been covered pretty well in other locations.To give a quick summary:
“Power Creatives,” like Peter Jackson and John Romero, are rare. They get to call the shots, they have diverse skills, and they bring value to any project.
How can you get there?
Know your weaknesses, and bring in partners to fill the gaps.
Delegate. Learn what you can do, and what you can’t.
Make it personal. Make games for you, about your experiences.
Design is sales. An idea has to sell. Not just money – you have to be able to sell it to your peers, too, so they’ll be excited about developing it.
Understand PR and marketing. You have to be public, brand yourself, and capture attention.
You’ll catch a lot of criticism, too. Take it and make it your own. Be distinctive.
You’re the frontman for your company’s band. Take that role and be distinctive.
Stay in touch with marketing, and keep control. You know your game’s image; don’t let them present the wrong one.
Understand your audience. Keep up with where videogames are going, and who’s playing them.
What’s in the future?
Games that reward multitasking. Devices that talk to each other. Carry a part of the game with you.
Reward often, and in the long-term. Create a visible calendar that keeps players anticipating the next piece of news or content.
In the future, AAA isn’t going to die, but it’ll be challenged by social games. Create long-term games, experiences that your players want to marry, not just date as a short fling.
Steam will help – more digital downloads, more instant gratification.
Tap in to the feed. This means Twitter feeds from characters, viral videos, and deeply buried Easter eggs. Get people talking! Get that free press coverage!
A power creative builds IP. Think about your game and your brand:
- Can you give a one-sentence pitch? Tweet it – 140 characters or less?
- What tattoos would people get from your game?
- What quotes will people use?
- What memes will you start?
The best ideas have cool gameplay, reinforce the game’s fiction, and show off your unique art/technology.
A Power Creative understands the business – or else the people who understand money will be happy to take yours!
Innovate! Never fall back on “Traditionally in this genre…”
Keep your IP sacred, it’s your most valuable asset. Parents introduce your IP to their kids. Fans write stories and make fan movies about your IP. Protect it, keep it, own it.
It’s risky to stick your neck out. Eh, whatever. Just do it!
Design in Detail: Tuning the Muzzle Velocity of the Assault Rifle on Legendary Difficulty across the Halo Franchise
I enjoyed this session a lot. Instead of vague design principles, it was about one single decision in the Halo games, how they came to that decision, and how the answer changed throughout different games.
Jaime Griesemer had done a lecture last year which was about balance, but this one was all about tuning. The difference is that balance is about longevity, keeping the game playable forever, making it fair, and making multiplayer work better. It has nothing to do with fun.
Tuning, on the other hand, is all about fun, making an experience feel good and immediate. It has nothing to do with making something fair or balanced.
Before we can come up with ideas for the speed of the assault rifle shots, we need to understand the context of our decision. The assault rifle is the most common enemy weapon, which means that it’s the most common shot that will be coming at the player. It also means that the player will scavenge lots of assault rifles, so they’ll be firing this gun often, too. The speed of this projectile really defines the feel of combat across the entire Halo series.
Fun actions have three things in common: they’re reactive (the player starts them), they’re repeatable (they’re not one-shot events or complicated to pull off), and they’re reliable (you get a nice impact and a cool result from this action every time).
To start, guess at what the extremes might be, then start narrowing in on the right value. They started with muzzle velocities from 1 to 20 unit/sec, and then tested and repeated until it felt right.
Jaime said that making the game harder just by turning up damage/turning down health is a mistake. Increased damage doesn’t make the game harder, it just punishes failure more. The shots are coming in at the same speed, it’s just that a mistake is lethal instead of just inconvenient. Making a game actually harder involves increasing the speed of the action, increasing enemies, increasing AI, and requiring better skills.
When tuning, avoid habituation – it’s easy to get on the wrong track, and start micro-tuning something that was the wrong idea to begin with. Take breaks from a project, then come back and see if the idea still feels fun. Try intentionally breaking things – set the values to a number that you know is completely wrong, then see how it behaves. Maybe you’ll realize that there’s another approach you should be taking.
Problem: When you split your available content in half, one half is going to be left behind.
When Left 4 Dead 2 was announced, a lot of gamers were upset that it was a standalone product, and not DLC for the first game. After getting some hands-on time with the game, I can safely say that Left 4 Dead 2 stands on its own. The feel of the game is different from its predecessor, and it evolves the Left 4 Dead formula without obsoleting the original game.
Therein lies the problem. Sometimes I feel like playing a campaign in the original game’s horror-movie style, and sometimes I want the faster action-movie feel of L4D2. The problem is that I need to make that decision from Steam’s game-launching window, rather than from the Left 4 Dead matchmaking window. When I click ‘Quick Match’ or ‘Find a Game’ from the Left 4 Dead 2 menu, I’m really only searching through half of the possible Left 4 Dead games out there.
Solution: Pop out matchmaking as a separate application.
A simple standalone matchmaking application would improve the value of the product for players who own both L4D and L4D2. Players could load this application, create lobbies, chat with each other, and select their campaign and game mode from all the options they own. Once they launch the game, the appropriate game engine would load automatically. It would increase the loading time, but it would ensure that Left 4 Dead fans are able to employ and enjoy all the content they’ve paid for.
Additionally, it increases the value and staying power of the Left 4 Dead campaigns and characters, by reducing the impression that this content is somehow old-fashioned or obsolete. I think this ties into an earlier post I made about Games as Platforms. I’m seeing Left 4 Dead as a platform, and I want to be able to just keep adding more and more content, campaigns, and characters into that platform.
We’re sure to see this problem again when Valve inevitably releases Left 4 Dead 3. Maybe they’ll implement a solution by then.
Problem: Once players are a few levels apart, they can’t effectively play together anymore.
Borderlands offers a lot of ways to play: single-player, drop-in multiplayer, and local splitscreen, and you can take one character and level them up in any mode. Starting a new game and playing with a friend works great…but if one player plays more than another, the fun starts to break down. Once the players are more than 4-5 levels apart, one of them is going to feel useless.
One option is for the lower-level player to host the game. But then the gameplay is trivial for a higher-level player, because their enemies don’t pose a challenge. They’ll rack up tons of kills, but feel bored doing it.
Or, the higher-level player can host the game. This is even worse – the lower-level player will die in just two or three hits, and their weapons will be unable to damage the foes they meet. It’s not just that they’re weak – they’re essentially not even playing the game anymore.
The players could agree to only play with each other, and make sure they keep their levels equal. But the ability to carry one character from single player to local multiplayer to online is one of the best features of Borderlands, and it’s not fair to expect the players to abandon that feature.
Solution: Equalize the characters’ levels, but offer the high-level players the high-level rewards they deserve.
When multiple players connect, the lowest-level character automatically sets the difficulty for the game. All of the enemies the group fights will be scaled to the lowest-level member. The higher-level characters take a penalty to their health, shields, damage, and skill effectiveness to bring them in line with a character of that level. The characters keep their skills, levels, and weapons; they’re just not as effective.
The twist is, the higher-level players continue to receive higher-level rewards. If a level 45 player is playing with a level 20 character, and kills a level 20 enemy, they receive XP as if they had killed a level 45 enemy. This may sound like a huge bonus, but remember – with the level-lowering, defeating a level 20 enemy should be as difficult for this player as defeating a level 45 enemy would normally be. XP is really a reward for the player, not the character, so they should receive a reward that makes the time they spend playing worthwhile.
Loot is a bit more complicated, since every player usually sees the same items. Rather than changing the loot drops, create a new way for high-level players to use low-level items.
Place a new vending machine in various cities around the world. Players can sell items to these vending machines, but they won’t receive money – instead, they’ll receive Loot Tickets. The number of tickets is based on the difference between the item’s level and the player’s level, and the player can’t receive tickets for an item that’s within 5 levels of their own, or a higher level than themselves. These tickets can then be traded in with these vending machines.
When checking this vending machine, every player sees a unique inventory screen, customized for their character. The machines show a broad selection of weapons and items that are appropriate to the character’s level and class, as well as an option to just give the player a random level-appropriate loot item. They can trade their Loot Tickets for these items.
In this way, the player has a reason to play with lower-level characters and pick up low-level items. The game still has challenge, and they can meaningfully cooperate with their teammates instead of overpowering them. They can continue to advance their characters at a meaningful rate, and transform the low-level items into stuff they can actually use.