Q&A: How Steam hit Raft stands out in the crowded survival genre

Raft is a clever game on Steam where you’re a survivor on a raft floating in the ocean, making use of flotsam drifting by to build up your wooden oasis into a substantial vessel, supplying you with food and drinkable water, while defending it and yourself against shark attacks and eventually finding locations in the vast ocean to explore and supply more resources.

Raft is developed by Redbeet Interactive, a Swedish studio made up of just seven people that got its start when three university students uploaded to itch.io a prototype of Raft, which gained unexpected popularity. The game's been in Steam Early Access since May 2018 and has proven hugely popular in the continuing run-up to v1.0.

The Redbeet team recently took some time to answer some of our questions about the design and development of the game.

Minecraft basically established the genre of creative survival games, but survival as a style has roots going all the way back to the Atari VCS, with the extremely rare Supercharger game Survival Island. What is Raft's place in this burgeoning field?

Hard to say. Most of us, if not all, have played Minecraft and between us, we have tried a lot of different survival games, such as Subnautica, Don’t Starve, Rust ,etc. We believe that one of the main reasons for Raft's success is the limitation of freedom, contrary to many other survival titles who use freedom to explore or endless procedural worlds as ways to market themselves.

Where many survival based games give the player the freedom to run around and explore, Raft keeps them trapped on their small raft for most of the game. This game mechanic is not unique to Raft and there have been similar approaches before, for example, the Minecraft mod Skyblock, but it is different from a lot of the other big titles and might have been what made Raft stand out.

A change since the early versions of the game has been placing the raft in a wider ocean, allowing players to navigate and explore, and even find islands and look around underwater. That seems like a big change to the game. Were you worried about it changing the nature of the play too much?

Not really. As these new explorable locations cannot be built on and since their resources are limited and do not respawn, the player always needs to keep going and maintain the raft as their base and home. The islands and underwater locations work more as pit stops and an addition to the current gameplay rather than a replacement. 

What do you think about the question of realism vs. playability, about allowing players to feel like this is an experience as promised by the theme, against making sure the game is playable and not frustrating? Like keeping your construction seaworthy, dealing with capsizing and weather?

Raft is an adventure game more than a simulation, and as with most adventure games, there’s some bending of reality. We usually try to base our mechanics and features in reality to keep the sense of immersion as strong as possible, but quite often we sacrifice reality to make sure the game is fun and enjoyable. We believe usability and gameplay should always come first.

The player is up against a constant stream of decay in the form of shark attacks upon their raft. In Minecraft, structure decay is part of the game (from Creeper explosions and Enderman block fiddling) but is largely preventable. Entropy seems like a much bigger part of Raft, with shark attacks being periodic and unavoidable. What role does this decay play in the game?

The role of the shark is quite simple. It is just there to put pressure on the player and make sure the player cannot just roam around on the reefs, or relax on their raft. In the early game, you have a small raft and you are preoccupied with expanding your raft and gathering food, so it is more of an actual danger compared to later in the game when its function is more to keep the player aware of how they build and where they place valuable items.

Let's talk about edge cases and fool-proofing. Is there any insurance in the game that the player will have the needed resources to survive? If their  aft is completely destroyed, is recovery possible? What about cases where they've built the raft up off the water, and they fall in? Can you construct multiple rafts?

There is not any actual fool-proofing, but in the design, we limit the ways in which they can completely screw up. There are cases where the player can reach sort of a game over state though. For example, if their raft is completely destroyed by either themselves or the shark, it is impossible to build a new one. This might get changed going forward.

Some of your islands are satisfyingly large. What amount of the game is bespoke content creation, and what amount is procedural?

All of the islands are built and designed by hand, however, the order and placement in which they spawn is procedural.

Now that you have a greater level of exploration in the game, you can actually leave your raft for extended periods of time. How do you handle issues like shark attacks and other decay of objects that are not nearby? Do you simulate it, fake it while away, or just call all that stuff safe until you get back?

As it is right now, it is still simulated no matter how far away the player is. So if the player explores an island for a long period of time, the shark will probably have chewed down a couple of foundations. With upcoming updates, the player might be encouraged to spend more time on islands and other types of destinations, so this might be redesigned, we’ll see.

Raft is interesting because the building you do is actually separate from the game terrain. Did you encounter any issues with mixing the navigable areas on the raft with those of an island, when you're near or on it?

There have been several issues with having a moveable, buildable raft. We’ve had issues with jittery and buggy collision between the raft and the islands and there have been issues with performance when simply moving that many colliders each frame. Luckily, by building systems to only keep them active when you are close and merging certain colliders into one, we have been able to keep the framerate at reasonable levels and lower the complexity of the colliding to achieve smooth collisions, at most times.