To be continued by whom? If the end of a scene says, "To be continued by anyone," you are welcome to join. If a writer has specified someone else by name, do not add a scene-- you would be interrupting someone else's story.

No mind control. For example, if you're in a sparring match, your opponent can aim, punch, or kick, but only you have the right to determine whether you are hit, knocked down, or killed in the Interactive Story. Similarly, you may not say that the other person is defeated or killed, unless she has declared it herself. Ask permission before "borrowing" someone else's character by making her speak or do actions in a story.

Write scenes as long as the ones you're responding to. If another writer has posted a two-page scene, do not respond with a two-sentence scene. If you write short scenes, join stories with other people who write short scenes.

If in doubt, ask before introducing significant changes. If you are not the leader of a campaign and would like to introduce a significant change to the story line, ask to make sure it's okay.

Don't shout! A new writer who accidentally commandeers your character or wreaks havoc on your plot may not know she's accidentally tread on toes. Remember, you too were once a new writer. Be encouraging and just point her to the right Workshop or page. You aren't obligated to include the changes she has introduced to your story-- you can always disregard the errant scene and continue as previously planned.