MUST READ

Be respectful of yourself and other players
Interactions with other players should not be abusive, disparaging, or inflammatory, nor create an environment that is unwelcoming.

Examples of disrespectful content include:
Insults or harassment
Threats or encouragement of harm
Trolling or baiting arguments
Discrimination
Bypassing word or content filters
Public accusations toward others

Be constructive and avoid off-topic content
Hubs and discussion threads all have their own purpose & topic. Make sure that contributions are relevant and constructive.

Examples of off-topic content include:
Spamming
Posting topics in incorrect hubs
Re-posting closed, modified, or deleted content
Derailing a discussion or topic
Bumping threads

Commercial content is not permitted
Unless otherwise specified, discussions are not a place for commercial activity.

Examples of commercial content include:
Advertisements
Referral promotions
Recruitment
Gambling & raffles
Giveaways with entry requirements

Don't discuss or engage in unlawful or prohibited activity
Any posts or activities that violate Steam's legal agreements are not allowed.

Examples of prohibited conduct include:
Encouraging or facilitating real-world violence
Exploitation of minors
Bypassing Steam's Mature Content Preferences
Doxing or posting personal information of other users
Scamming or deception
Encouraging or engaging in piracy or theft