Moderators are assigned individually for channels by the channel owner. If you are looking to be come a moderator in a stream you frequent, I would recommend becoming active in their community and show that you have the qualities to become a good moderator.
Make sure you don't simple just ask to become a mod because it is generally frowned upon and will probably make you less likely to be chosen.
i think he means like saucebot they are always moderators evry where they join
SauceBot is just a normal account that connects via IRC and uses scripts (it has no special privileges whatsoever). Once its joined a channel, the channel owner (Broadcaster) has to Mod SauceBot on their own terms.
Comments