The Game Design of Agar.io
“I’m going to eat you….”
When Agar.io came out in 2015, it quickly took the gaming world by storm, with its simple controls and a concept that’s easy for anyone to understand. Venturebeat recently talked about the surprising momentum it garnered at a time when browser games seemed nearly obsolete. And Forbes talked about the ‘hynoptic addiction’ of a rival competitor, Slither.io. Of course, the addicting qualities it possesses are all down to games design.And of course, it’s great fun too!
In this article we’re going to get on our game design hats, investigating some of the design choices in Agar.io, and see what makes them so effective. What is it that makes this game so good?
Break it Down!
The main game mechanics in Agar.io are that of a food chain. You play as a cell in a petri dish, and can move around “eating” smaller cells than you. Eating makes you bigger – the larger the “meal”, the more you grow. You can also be eaten! The other moving cells in the petri dish are other players. That’s the basics.
The Food Chain
What’s interesting is that these simple mechanics lead to dynamic gameplay. The game cycle is:
- Scavenge and Survive – At the beginning you’re a vulnerable little weakling, surrounded by larger enemies. You need to eat little cells on the ground and avoid every other player. You are prey, a scavenger. Gameplay is about dodging, escaping – surviving.
- Eat your Enemies – Once you’ve grown a bit, you’re now big enough to eat some other players. The dynamic shifts a little. You’re still prey, but also a small-time hunter. The gameplay adds chasing, you make decisions about who to chase, and who to avoid.
- Get Big – If you continue to hunt and survive, you’ll get big. But the bigger you get, the more tempting a target you become to other players. Why? Because they get more reward when they eat you – risk and reward is a common tool in the game designers’ kit to add fun.
What Makes it Tick?
Firstly the survival aspect is what makes Agar.io work. Other players are big, and scary – especially the most massive ones. Surviving is a fun challenge.
Secondly is the sense of empowerment you get from becoming a predator. The bigger you get, the easier it is to consume other players. This is very satisfying – especially as you know it’s real people that you are beating. And it’s even more rewarding because you worked your way up there from being tiny yourself. You feel strong and powerful. Working your way up the food chain is a compelling goal.
Divide and Conquer
After the food chain, the other big mechanic is that you can divide your cell into smaller pieces. They move faster and merge into one cell again after a while.
The ability to divide is a clever mechanic. Why? Because it allows a number of interesting things to happen:
- You can use the divide as an attack to eat another player. The bigger you are, the slower you move – so dividing becomes the easiest way to eat smaller players who are too fast to catch.
- You can use the divide as a defence to speed you up. As your cells are smaller, they move faster. You can sometimes use this to speed away from a bigger threat.
- But dividing comes with risk. When divided you are split into smaller cells. That means that you can be eaten by more players. This means when you divide, the balance of the game shifts. You might have been one of the biggest cells, but when you divide you are temporarily vulnerable to other players who can eat some, or all of your newly divided cells.
Dividing brings both strategy and balance to Agar.io.
- It forces the big players to split their cells to attack, giving smaller players a chance to catch up.
- It creates more risk and reward as players will rush to assimilate one big player’s split cells before they re-merge.
- It creates a way for players to sacrifice power for mobility – allowing them a chance to escape, but at a cost.
Another clever mechanic – these spiky blobs automatically divide large players who run into them. But smaller players can hide under viruses for shelter. This creates risk and reward for big players chasing small players around viruses. It also gives vulnerable little players a helping hand.
Viruses can also be spread by “firing” parts of your cell at them. This makes them another balancing tool to help topple the biggest players at the top of the food chain.
Agar.io has no mini-map or radar of the arena and the players. Why is this important? Well, a lot of the fun hinges on the unknown. You have to react suddenly to situations. It makes it hard to predict where players are going. Little players have a chance to escape out of view. Big players can suddenly appear unexpectedly. Viruses can be seeded to catch the unwary. It’s a small design choice but imagine how different the game would be with a map.
Made You Think?
I hope this has given you a bit of insight into how game design works. Agar.io is a great example of how some simple, but clever, game design mechanics have created a really fun and balanced game. Of course, the players themselves add a lot of the chaos and mind-games, but none of that would be possible without the solid ruleset in place.