How hard is to add co-op in a game? (questions inside) Options

[rafoca]

Hi, Andres.

I want to ask you a few things about development for I am very curious about why so many companies decide to not include co-op or even take this feature out later on development.

Some of them say that co-op can´t be done in some game, but I always knew that this wasn´t the main reason they weren´t adding or axing co-op.

So I ask: Is that so hard to make a co-op game? why?
Is it more expensive?

What is harder: making co-op online or offline? Making a co-op campaign or a co-op mode? A lot of companies, these days, already know that co-op is awesome and may help sales, but they choose to make a secondary style of co-op that rarely is as good as play the main campaign with a friend.

Do you have to downgrade graphics to make co-op work? I noticed that co-op games, even when played alone, tend to have inferior graphics when compared to single-player games. Also, I noticed that split-screen, when activated, really downgrade graphics.

I thank you for your patience. I always wanted to ask these questions to a dev

[Andres Bordeu]

Some of them say that co-op can´t be done in some game,

This can be true or extremely difficult depending of the way the game is designed.

So I ask: Is that so hard to make a co-op game? why?
Is it more expensive?

Depends what you're aiming for, but making a co-op experience will always be considerably more difficult than a single-player experience. That's because every variable has to take in to account interactions with two simultaneous players. Take something as simple as a door opening. In single player you program the character to animate through it and that's it. In co-op you'd have to think about what happens if the other player is standing on the other side of the door, blocking the direction the door opens. How does the first player open the door if the other player is blocking the path? How would you fix it? Multiply this problem for every other interaction where two players can interact and you can quickly see how the complexity rises, and we're not even talking about matchmaking and other online problems.

What is harder: making co-op online or offline? Making a co-op campaign or a co-op mode? A lot of companies, these days, already know that co-op is awesome and may help sales, but they choose to make a secondary style of co-op that rarely is as good as play the main campaign with a friend.

What do you mean by offline co-op? Split screen co-op? Depending of the game this presents different challenges. I guess many companies decide to make special co-op campaigns because the main campaign is too complex to have two players in it, so they create simpler environments where the complexities of having two players are more limited. Think the difficulty of adding co-op, even from a narrative point of view. If a game relies heavily on cutscenes, how do you plan them in a co-op environment? What if the player is playing alone? Should you see a different cutscene? Additionally any online game mode will present the challenges of having a matchmaking system, which is a complex design and technical task.

Do you have to downgrade graphics to make co-op work? I noticed that co-op games, even when played alone, tend to have inferior graphics when compared to single-player games. Also, I noticed that split-screen, when activated, really downgrade graphics.

Only if you do split screen co-op, should there be downgraded graphics. This has to do with the difficulty of having the same hardware manage the resources of two separate screens simultaneously. Memory in these cases generally becomes an issue.

[rafoca]

Great answers!! Thanks!!

By offline co-op I really meant split-screen co-op.

When you say split-screen is the only co-op feature that may downgrade graphics, is is just a coincidence that co-op games tend to be less beautiful? So do you think that every single-player game out there could look the same even with co-op campaign, given the right resources and people to work on it?

But what about framerate issues? I heard that the more players you add in a campaign, the more framerate issues you may have (Peter Molyneux said that in Fable 2, I remember), so wouldn´t that require some downgrade in graphics to make framerate adjustments?

I am just asking. I am not confirming anything. I am very curious haha

[Andres Bordeu]

If you have online cooperative each hardware system (PC or console) should manage the rendering and processing of it's own FOV / gameplay, so there's no reason that should affect framerate drastically. The amount of data your game sends through your connection can affect though.

Having lots of more characters in a match (players or NPCs) means you'll need more processing power too. If your co-op game needs more characters to balance difficulty that could produce a performance impact, but I can't remember of much games where the entity count is drastically higher between solo sessions and co-op sessions. I think that in multiplayer games that can have many simultaneous characters in one game session framerate can be more of an issue.

Please take in mind that most of what I'm discussing I'm assuming we're in a FPS environment. A lot of this will also apply to other game genres, but not so much for some.

[rafoca]

Thanks again. I am enjoying a lot these informations.

Now I understand what Peter said about framerate... Fable 2 has offline co-op! He meant framerate issues because of that. Exactly what you said.

So my theory of co-op games being not as good looking when compared to other games may only make sense because of time constraints? I mean... suppose you have a year to finish a game, but you also have to put co-op in it... it may not have enough time to do everything in perfect state then. It also may have something to do with money or people available to work on the project and even if these people working are qualified to do it.Am I right?

[Andres Bordeu]

Yes, that sounds correct (making a co-op game is harder than a solo game, thus it requires more time &/or money). But the end result will depend mostly of each project's budget and schedule.

[rafoca]

Yes, that sounds correct (making a co-op game is harder than a solo game, thus it requires more time &/or money). But the end result will depend mostly of each project's budget and schedule.

I see.

What about those games that you are playing co-op with an AI all the time, but you can´t play with friends (Dragon´s Dogma being the most recent example)? What do you think happened? I mean... the co-op is there, but can´t be played by any real friends...

[Andres Bordeu]

It's a completely different scenario because the AI character is limited to specific actions, thus the designers are working with a more "controlled environment". With a second player that's not the case.

[rafoca]

I understando now. Thanks!!