A guest is a non-registered ROBLOX user. They can play games and chat in Super Safe Chat mode. The purpose of guests is to give people who have not registered a chance to try ROBLOX, before spending the time to sign up. A guest's name will always be in the format "Guest #", such as "Guest 1978". All Guests will take on the appearence of ROBLOX in-game, and will have a negative Player.userId.
Any ROBLOX user with no space between "Guest" and the number is not a real guest, and should be reported - guest impersonation is against the rules.
Some long term roblox users get angry and irritated with guests because they are still learning, or because they don't understand the game and may accidently team kill etc. Do your best to be friendly and tolerant with guests, as they are potentially future roblox users! Treat them like a person, not an idiot. Do not publish or give out scripts that deny guests from joining games, that is against the rules. Guests are one of the main ways that ROBLOX gets new members.
Guests were introduced to Roblox in September 26, 2008, with the reason that some people could want to try out ROBLOX to see if it’s any good before they take the time to make an account. Back then guests had a yellow head and arms, a blue torso, and green pants .
Some time in 2009 Roblox updated the look that guests had, guests would now look exactly the way the player "Roblox" did, they had a white head, black pants, and a black shirt that said "Roblox" on the front, and "make a free account to change how you look!" on the back .
On March 23, 2011, Roblox added the ability to choose the gender of your guest, a system that is still in use today , girl guests get pink hair and a girl torso , and boy guests get a red Roblox cap .