gameProperties

A set of key-value pairs that can store custom data in a game session. For example: {"Key": "difficulty", "Value": "novice"}. You can use this parameter to modify game properties in an active game session. This action adds new properties and modifies existing properties. There is no way to delete properties. For an example, see Update the value of a game property.

Avoid using periods (".") in property keys if you plan to search for game sessions by properties. Property keys containing periods cannot be searched and will be filtered out from search results due to search index limitations.