Before starting the server, there is an option in the server.properties that sets the default game mode. If you are using the Multiverse plugin, you will need to set it in plugins\Multiverse-Core\ for each world.
While the server is running, either type gamemode [player name] 1 in the console or (if you're an op) /gamemode [player name] 1 in the chat to set creative mode for an individual player, which can be yourself or someone else.
In either case, 0 means survival mode and 1 means creative mode.
Chat with our AI personalities
/gamemode your name 1Then the same with 0 to turn it off. IF your an OP or admin.Type in "help" or "?" in the server window to get a list of server commands.
If you are the server owner (or can get the owners to change game mode or just yours) you can switch it to creative mode in the server conf file or by command in game by and op. otherwise a server in survival mode is staying in survival mode.
The server option for online mode must be off.
No, multiplayer has no effect on your already existing single player worlds.
(this only works if you have singleplayer commands or if your a mod or up in a multiplayer server) /gamemode (name here) (1 for creative 0 for survival) ex: /gamemode blabla34 1 creative or to switch from survival to creative and back just do: /gm