System Messages are a helpful tool for a few things. In WOS, you can have messages created when players join or complete a difficulty, and helpful tips or promotions in the chat.

Join And Leave

This is the simplest of the 3 and is enabled by default. It sends a message to all users that is displayed in their chat that a player has joined or left the game. The message can be changed, but the default is "@{username} joined/left the game."

Rotational Messages (Tips/Promotions)

This is what most people associate with System Messages. This feature takes preset messages and sends them to all player's chats to be displayed. However, unlike a lot of games, these system messages are handled on the server, so everyone gets the messages at the same time and is not confused.

Difficulty Completed Messages

This feature is slightly harder to explain and is more advanced. To put it simply, when a player reaches the end of a section in the obby, you can set the difficulty name and color, so for example, a chat message can appear like "@{username} completed {difficulty_name}," and it could be green, grey, blue, etc.