Games are not like Thanksgiving turkeys. Playing an unfinished game is probably not going to hurt you. You can’t say the same about an uncooked holiday bird.

Valve, however, recognizes that giving people the opportunity to play incomplete games is a risky endeavor, and it’s updating its rules (again) for developers to ensure a good experience for everyone involved (as Giant Bomb first spotted). Valve runs the Steam digital-distribution service for PC games, which has a portal dedicated to “Early Access” games that are still in development. This has enabled big hits like DayZ, Rust, and Kerbal Space Program to generate revenue and experiment with features while their studios continue working on them. But some games have fallen apart after accepting money, and Valve wants to make sure every customer is aware of the potential for things to go wrong with Early Access.

Games are changing. Blockbuster development is calcifying around a handful of megapublishers while mobile continues to make millions for a small number of companies. Early Access and crowdfunding sites like Kickstarter are enabling smaller teams to experiment in PC gaming. But a few headline-grabbing failures could destroy the reputation of those platforms, and Valve wants to prevent that from happening.

“When you launch a game in Steam Early Access, there is an expectation by customers that you will continue development to a point where you have what you consider a ‘finished’ game,” reads the new guidelines for developers considering Early Access. “We know that nobody can predict the future, and circumstances frequently change, which may result in a game failing to reach a ‘finished’ state, or may fail to meet customer expectations in some other way. We work hard to make sure this risk is communicated clearly to customers, but we also ask that developers follow a set of rules that are intended to help inform customers and set proper expectations when purchasing your game.”

The big rule that Valve is pushing on developers is that if a game is on Early Access, studios must clearly label the game as unfinished everywhere they communicate about the game. If a team sends out review keys of its Early Access product to a YouTube personality or editors at website, the email with the key must mention the game is not finished. This should also help prevent third-party retailers from selling Early Access Steam keys as complete games.

“We work really hard to make sure that customers understand what they are buying when they get an Early Access title on Steam,” the rule book continues. “But we’ve seen that many of these titles are sold as keys on other websites where there is no explanation of what Early Access is or what the current state of your product is now versus what you hope to achieve.”

Valve also wants developers to avoid announcing promises about future content. The company argues that no one can predict the future and anything could derail production. More importantly, Valve doesn’t want studios selling a promise. Early Access developers must sell the game they have and not a possible future game that may or may not actually happen.

The Early Access documentation for developers also includes several tips that Valve wants studios to keep in mind. These include common-sense bullet points like don’t release an Early Access game unless you can afford to continue developing with very few or even no sales. The company also advises against launching tech demos or finished games.