How the team behind Zelda made physics feel like magic

The Legend of Zelda: Tears of the Kingdom is a phenomenal game, appreciated for being able to improve and iterate breath of the wild, In the weeks following the game's release, it was written about with all kinds of breathless praise as people wondered how Nintendo managed to create a game that far surpassed the technical capabilities of the now seven-year-old Switch hardware.

For developers, the game seemed like magic, But during a talk at the 2024 Game Developers Conference, Nintendo shared that it wasn't magic but rather a specific, well-executed development strategy that still felt magical.

During the conversation, technical director Takuhiro Dohata tears of stateexplained that the game had two key driving principles: “an expansive and seamless Hyrule” and “qualitative gameplay.”

The first was relatively simple. “We wanted players to see things far away and players to go there,” Dohata said. This philosophy was carried forward from here breath of the wild, with the new challenge of seamlessly connecting the sky, surface and underground. We can see how that integration worked tears of state Link's free-fall pose as he descends from the sky to the surface and then between the surface and underground. The action links together three different worlds of Hyrule.

However, Dohata cautioned that creating a big, interconnected world doesn't mean it will inherently be fun. The fun, he explained, comes from the second principle: qualitative gameplay.

Dohata defines qualitative gameplay as a system by which players combine actions and objects to create their own ways of playing. Dohata explained that the developers did not want to create fun through individually designed moment-by-moment gameplay events, rather they wanted to create a system that “allowed the fun to happen.”

The seeds of this “let the fun happen” system first germinated breath of the wild and its Octo Balloon, a monster part that Link can attach to heavy objects to make them float in the air. For tears of stateThe developers expanded that idea to stick all types of objects together resulting in the Fusion and Ultrahand abilities – powers that let Link combine objects to create weapons, objects, and structures.

But for qualitative gameplay to truly work, every interactive object in Hyrule has to behave in specific and predictable ways. This required Takahiro Takayama, tears of statePhysics Programmers has described it as a “completely physics-driven world”.

The first problem that arose was the collision between physics-driven objects and rigid-body objects created by Takayama. Rigid body objects are objects whose every property – mass, velocity, weight, and more – is specifically designed, regardless of its form. in a hurry tears of stateDuring development, various gear mechanisms in Hyrule were rigid body objects. Meanwhile, the properties of a physics-based object are governed by physics; The large metal boxes littering the Sky Islands above Hyrule are an example of this.

Takayama explained that although rigid-body objects were easy to create, they create all kinds of problems when thrown into the mix with physics-driven objects. Like matter and antimatter, when a physics-driven object interacted with a rigid-body object, the world broke apart. One example involved clipping rigid body gear through a metal box that was inserted between them. The solution to this problem was simple. Takayama said, “Being inspired by physics, without exception, everything is necessary to make qualitative gameplay a reality.”

With everything being physics-driven, every interactive object in Hyrule will behave exactly as a player would expect it to – the metal box now prevents the gears from rotating.

Hyrule then becomes “a world where players can express their creativity without fear,” Takayama said, “a world where anything can happen depending on the player's imagination.”

Takayama said that making everything physics-driven eliminated the need for “dedicated implementations”. This would involve creating a program for each function and interaction. Without a physics-driven system, each of Link's actions would require its own special program to execute. If developers want Link to drive some type of vehicle, they will have to create a dedicated program that controls the vehicles.

Although it was technically challenging to operate every object in Hyrule physics, it reduced the need to create so many dedicated programs early in the development cycle.

Takayama explained, “Instead of creating a vehicle program, we created a system in which vehicles could be built.”

The difference may seem subtle, but that subtlety is where all the “magic” lies tears of state gives. When developers very nervous tears of statebridge physicsI was wondering how they programmed the bridges to behave properly without any glitches, the truth was that they created systems that controlled each individual component of the bridge: its slats, links, and even That there are various forces like wheels that will interact with it. Even the game's music used this modular approach. Junya Osada, tears of stateThe sound designer explained that the game's wagon sounds did not come from his team going out and recording a horse-drawn wagon.

“There is no sound of a wagon but the sound of wheels, chains and creaking joints,” Osada said.

These systems facilitated emerging gameplay types. tears of state Such a special game. Players were able to use them in ways that the developers themselves had never thought of.

An example of these systems at work is the humble portable pot Zonai device. In breath of the wild, cooking used to be done in dedicated locations, but with portable pot links cooking could now be done anywhere. Because everything, including cooking ingredients, was physics-driven, the developers faced a problem: if Link decided to cook on the side of a mountain, all of his ingredients would spill out of the pot.

With dedicated implementation, the pot will cook easily no matter where it is placed and nothing else. However, the multiplicative gameplay philosophy ensured that no matter where the pot was placed, the cooking surface would be oriented horizontally so that your soup would not spill. This gave the pot a larger purpose beyond cooking, allowing it to be used as a ball-and-socket joint, leading to all kinds of bizarre creations.

Nintendo's tears of state The panel explained that the game's success was guided by the idea that players should find themselves entertained under a robust physics system that applies to every single object in the game. But the conversation revealed another, unspoken reason that contributed to tears of state Being on every 2023 Game of the Year shortlist: Nintendo keeps its brilliance intact.

in an industry where Average career length measured in single digits, each speaker worked for Nintendo for at least 10 years. This type of retention is a huge factor in Nintendo's continued success. Institutional knowledge is preserved and teams are able to work together more easily with limited disruption due to turnover. Although Nintendo Not a perfect company by any meansIt appears to understand that the best way to get good games is to employ and retain good people.

“Working closely with game designers and artists who understood the vision was essential to bringing this massive world to life,” Dohata said.