The subject matter of the content.

A sub property of object. The options subject to this action.

A category for the item. Greater signs or slashes can be used to informally indicate a category hierarchy.

A piece of data that represents a particular aspect of a fictional character (skill, power, character points, advantage, disadvantage).

A sub property of object. The collection target of the action.

An item within in a data feed. Data feeds may have many elements.

The default value of the input. For properties that expect a literal, the default is a literal value, for properties that expect an object, it's an ID reference to one of the current values.

For failed actions, more information on the cause of the failure.

Indicates an item funded or sponsored through a [Grant](http://schema.org/Grant).

An item is an object within the game world that can be collected by a player or, occasionally, a non-player character.

The electronic systems used to play [video games](http://en.wikipedia.org/wiki/Category:Video_game_platforms).

The object that helped the agent perform the action. e.g. John wrote a book with *a pen*.

An entity represented by an entry in a list or data feed (e.g. an 'artist' in a list of 'artists')’.

For itemListElement values, you can use simple strings (e.g. "Peter", "Paul", "Mary"), existing entities, or use ListItem.<br/><br/><br/><br/>Text values are best if the elements in the list are plain strings. Existing entities are best for a simple, unordered list of existing things in your data. ListItem is used with ordered lists when you want to provide additional context about the element in that list or when the same item might be in different places in different lists.<br/><br/><br/><br/>Note: The order of elements in your mark-up is not sufficient for indicating the order or elements. Use ListItem with a 'position' property in such cases.

The item that is being reviewed/rated.

Of a [Person](http://schema.org/Person), and less typically of an [Organization](http://schema.org/Organization), to indicate a topic that is known about - suggesting possible expertise but not implying it. We do not distinguish skill levels here, or relate this to educational content, events, objectives or [JobPosting](http://schema.org/JobPosting) descriptions.

Indicates the primary entity described in some page or other CreativeWork.

Indicates that the CreativeWork contains a reference to, but is not necessarily about a concept.

The object upon which the action is carried out, whose state is kept intact or changed. Also known as the semantic roles patient, affected or undergoer (which change their state) or theme (which doesn't). e.g. John read *a book*.

A sub property of object. The options subject to this action.

The tangible thing generated by the service, e.g. a passport, permit, etc.

A goal towards an action is taken. Can be concrete or abstract.

The task that a player-controlled character, or group of characters may complete in order to gain a reward.

A sub property of object. The object that is being replaced.