Game Design Deep Dive: #IDARB's wonderfully disruptive 'Hashbombs'

#IDARB lets any viewer meddle with live, competitive multiplayer #IDARB matches via Twitch and Twitter hashtags. But how was developer Other Ocean able to make it work?

Game Design Deep Dive is an ongoing Gamasutra series with the goal of shedding light on specific design features or mechanics within a video game, in order to show how seemingly simple, fundamental design decisions aren't really that simple at all.

Check out earlier installments on the unique touchscreen control of Helix and on the plant-growing mechanics of Grow Home

Also don't miss these developer-minded looks at the tutorial system in Rogue Legacy and Alien: Isolation's save system from our ever-growing Deep Dive archive.

Who: Mike Mika, Other Ocean

My name is Mike Mika, and I lead the design of #IDARB for Xbox One. I’m the design director for Other Ocean and I’ve been making games professionally since about 1996. Before #IDARB I was most recently known for hacking Donkey Kong so that my three year old daughter could play as the “girl.”

What: Hashbombs in #IDARB

I’m going to explain how we implemented Hashbombs in the game #IDARB, enabling thousands of people to wreak havoc on a live game without having the gameplay experience devolve into a hot mess.

A Hashbomb allows anyone watching a game, whether locally or from across the world, to interact with the game by whatever means they have available. Viewers can turn out the lights, turn everyone into clowns, flood the arena, all in the name of good fun. In the launch version, we included roughly 100 Hashbombs that enabled the audience to do a wide variety of things.

This is how #IDARB's Hashbombs work (note the hashtags in the ticker at the bottom of the screen)


But what is fun for thousands of spectators can easily turn into frustration for the people playing the game if we didn’t create a set of guidelines and design criteria for us to measure each new Hashbomb against. Each bomb would need to affect both teams equally at all times. If it obscured the vision of someone on one side of the screen, it would need to do that to the other. If it gave a player a special power, it would give all players that special power. We also would need to limit the simultaneous effects of multiple Hashbombs. We did this through careful pacing of the activation of the bombs, and by creating rules for bomb types. If one bomb obscured the screen while another obscuring bomb was activated, the new bomb would fail itself, to prevent extending the effect.

In the case of the #block hashbomb, viewers can block the goal. Initially, you could block red team’s goal or blue teams’s goal. Like most ideas, we implemented them without thinking too much about it. Obviously a spectator could spam one of the team’s goals, especially if there was only one person Hashbombing. To fix that, we block both goals with one simple command. Although, if #block was continually being spammed, it made it very hard for any team to score. Our solution was to rely on the scroll speed of the incoming bombs, and that became our guide.

The game only activates the Hashbomb when the scrolling text reaches the center of the screen, giving players time to know it is coming if they are paying attention and prepare for it, and it also allows the effects of most of the previous bombs to play out. This metered pace creates enough time between bombs for players to deal with their effects, and prevents “stacking” of bombs, which would result in situations impossible for players to navigate. (For example, turning out the lights and activating penalty lasers.)

Mike Mika

We still had to deal with the Hashbombs coming from multiple sources. This was handled by interleaving the incoming bombs. If we have bombs coming from both Twitch and Twitter, we alternate between the incoming feeds. Also, if we are accumulating too many bombs, we randomly drop them to allow the stream to catch up.

Before #IDARB, there was no Twitch or Twitter integration to the scale of #IDARB, so many of the game’s features were implemented blindly and were never actually tested under a true load of players until it launched. There simply was no feasible way for us to test it. The game was created with complete transparency, but it flew under the radar of most gamers, which helped during the development phase. We didn’t have to shroud the game in secrecy, and we publicly tested the social media integration without concern that someone was watching.

Why Hashbombs?

While we were designing #IDARB, we wanted to keep the viewer interaction as accessible as possible. A lot of games use companion apps to interact, but that can be too big of a barrier to entry for most people. The space on their phone is sacred. We really wanted people to rely on the social tools they already use on a daily basis. For this game, those social tools were Twitter and Twitch.

"[#IDARB] became a bizarre curiosity that resulted in just over a million downloads in its first week of release."

We knew the game would be streamed, and if we could tap that audience, we’d be moving into undiscovered country; a place where millions of gamers hang out to simply watch games. What if we could encourage those viewers to interact by simply tweeting or chatting to it? Also, if we implemented it correctly, we’d have everyone tweeting the game’s name to activate a Hashbomb, which in turn would promote the game.

That was our mission. If we did it right, we’d benefit from the viral nature of the experience, and it’d be almost as fun for viewers as it was for the players. Hashbombs like a perfectly timed “#block” by a viewer is incredibly rewarding. If we failed, we’d lose nothing in the trying. The core game was already fun.

The Result

We launched with all the Hashbomb systems tuned as best as we could, and it most definitely wasn’t perfect, but we were surprised to see that it held up. We’ve had streams of up to 30,000 viewers all spamming the game -- a scenario we never tested for, but the game (and players) somehow survived the barrage.

We thought we understood the magnitude of tapping the streaming audience, but we never knew how much we would rely on them for getting the game out there. We released the game officially on February 1st, 2015, but handed out early release codes to nearly 1600 people during December and January. Probably less than 100 of the players we gave codes to regularly stream their games, and they immediately took the game live. It was kind of unique in that it was a game that was not released yet, so curiosity resulted in higher-than-normal viewership for many streamers. Also, giving the spectators the ability to interact with the game, was in a sense, like Prometheus bringing fire to early man. The word-of-mouth exploded as people searched streams for the game to interact remotely. By the time the game officially shipped, those early streamers had created a lot of positive buzz around the title (and we’re indebted to them!).

If you searched for the game, you found nothing but praise and excitement. It became a bizarre curiosity that resulted in just over a million downloads in its first week of release. It also helped that #IDARB launched free as an official Games with Gold title. The ability to engage so many spectators made it a favorite among live game streamers on Twitch and soon it was included in the game rotation as it attracted so many viewers. The net result was a win-win for the game and the streaming community -- #IDARB is now being played in bars across the country, on a million plus Xboxes, and has been called one of the best multiplayer games in the last few years. By not limiting ourselves to just players with controllers in hand, we opened the game up to millions of untapped players.

For more on #IDARB's development, check out "The crowdsourcing crash course of #IDARB" on Gamasutra.

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