Sean Plott, better known as Day[9], is famous for streaming games like StarCraft II online. He argued, in his GDC Next talk, that developers can and should make their games better for streaming, and explained how. Twitch has 45 million uniques a month, and viewers typically stick around for 90 minutes. "With the rise of online video there's now an incredibly easy free way to make marketing tools for your game that people are hungry to watch," says Plott. "Most importantly, it's native to what a game is." "If you can make it easy, convenient and fun for the community creators to make their own content then great, you get free marketing." And you build a community around your games if you do it right: "Online video is about community... with video, we have comments, linking and Tweeting, people are encouraged to send each other videos. It's about your community doing it for you." Almost 50 percent of video content for a game on YouTube is community-generated, says Plott. And a huge proportion of this, of course, is pure gameplay video. "In thinking of the online video audience you are thinking about how to make the gameplay itself viewable.

Making a Game Pleasurable to Watch

One thing Plott emphasized is that a game has to be easy and pleasurable for not just "influencers" and pros to stream, but for all players. That's because "you want to make sure there's a constant rise up" of novice players to community contributors. And if your game is appealing when streamed, you have a chance to capture both viewers "who have this game as a lifestyle hobby" as well as new players: "They want to stop in and watch some gaming content and you want the easiest, smoothest path for them to become hardcore players," says Plott. And you have to think about what your game will look like to a new player when viewed by a newcomer. They didn't sit through all of your tutorials and play for tens of hours -- but they should be able to understand what they see. "There needs to be a way for a new guy to hop in and get what I call 'game summary information,'" says Plott -- information like a player's objective, how powerful they are, and more. If a new player can, at a glance, get a bead on the game, they'll be more likely to stick around.

Mind Mechanics and Chunkiness

Games with strategic decisions are particularly well-suited to streams, says Plott: "The core, fundamental question in mechanics that makes a game fun to watch is 'What would I do differently?'" This applies to skill-based games like Street Fighter, League of Legends, or Super Meat Boy and also sandbox games like Minecraft or SimCity... but not so much single-player linear games. But ones with choices (The Walking Dead) or possibiltiies of different play styles (The Last of Us) do well, Plott says. But most important, perhaps, is what he calls "mind mechanics" -- where players can anticipate what the player will do and discuss it. Plott referred to Blizzard's collectible card game Hearthstone in this regard. "There's a single action," he says, after careful deliberation. The player makes one move. "The viewers get that first 80 percent of gameplay, they can watch and see the cards and make these same deliberations on their own; the only difference" between the player's experience, and the audience's experience "is when the last step gets chosen. The last moment is what everybody wants to talk about." Not all games work this way, and that's okay. Think Super Meat Boy: "Is there a way for someone to record a two or three minute feat in your game that is amazing?" Games that are broken into discreet chunks are good, too: "Is there a way to record just a chapter of the game?"