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For most people, the distinction between a game and a toy is that games rely on a defined set of rules. They dictate how players should experience a game and give structure to a designer's creation.

But for indie developer and Santa Ragione co-founder Pietro Righi Riva (Fotonica), rules aren't everything. At this year's GDC Europe, he argued that truly great games aren't defined by their rules, but emerge naturally if designers give players the freedom to experiment on their own.

"Games happen," Riva said. "They happen largely in the minds of players and not in the things we give them, so you kind of have to let go and stop worrying... We don't really design the games, we design these things, and we hope games will take place in the way we expect them to."

Riva pointed to popular titles like Dear Esther, Minecraft, Animal Crossing, and LittleBigPlanet, noting that they all allow players to piece things together on their own, explore new ideas, and find their own meaning among the tools at their disposal.

"The people who designed these games felt like they could inspire players to make something out of what they are giving them," Riva said.

He even pointed to a quote from world-renowned street artist Banksy, saying that his philosophy for painting very much applies to games. As Bansky says, "The Holy Grail is to spend less time making the picture than it takes for people to took at it."

If game developers can manage that with their own creations, then Riva says they must be doing something right.

In Riva's full presentation, he explains how he applied some of these design philosophies to his games like Fotonica and MirrorMoon, and you can see the entire talk for yourself in the above GDC Vault video.

About the GDC Vault

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Be sure to keep an eye on GDC Vault for even more new content, as GDC organizers will also archive videos, audio, and slides from other events like GDC Online, GDC China, and GDC 2013. To stay abreast of all the latest updates to GDC Vault, be sure to check out the news feed on the official GDC website, or subscribe to updates via Twitter, Facebook, or RSS.

[This article was originally posted on Gamasutra.]