A messaging system comprising: a messaging component configured to effect instant messaging communication sessions between users of the messaging system; a user database configured to hold user identifiers of the users; template storage configured to store action templates; a template creation interface configured to receive, from a template-creating user, template creation data for creating a custom action template and associated data identifying a subset of the user identifiers; a template manager configured to create in the template storage a custom action template according to the template creation data; an action database configured to hold actions; and an action manager configured to generate each of the actions in the action database, in response to an instruction from an action-generating user, according to one of the action templates available to the action-generating user, wherein the messaging component is configured to transmit a message to a user device of at least one action-receiving user to render data of the generated action accessible to the action-receiving user in an instant messaging communication session, characterized in that the template manager is configured to associate the custom action template with the subset of user identifiers so as to render the custom action template available to only the users having the subset of associated user identifiers; and the messaging system is configured to cause a user device of the action-generating user to display, to the action-generating user distinct from the template-creating user, a user interface including a plurality of selectable action generating elements for generating actions within the instant messaging communication session, wherein each of the plurality of selectable action generating elements represents an action template and wherein the plurality of selectable action generating elements includes a selectable action generating element representing the custom action template based on whether a user identifier of the action-generating user is included in the subset of the user identifiers. a messaging component configured to effect instant messaging communication sessions between users of the messaging system; a user database configured to hold user identifiers of the users; template storage configured to store action templates; a template creation interface configured to receive, from a template-creating user, template creation data for creating a custom action template and associated data identifying a subset of the user identifiers; a template manager configured to create in the template storage a custom action template according to the template creation data; an action database configured to hold actions; and an action manager configured to generate each of the actions in the action database, in response to an instruction from an action-generating user, according to one of the action templates available to the action-generating user, wherein the messaging component is configured to transmit a message to a user device of at least one action-receiving user to render data of the generated action accessible to the action-receiving user in an instant messaging communication session, characterized in that the template manager is configured to associate the custom action template with the subset of user identifiers so as to render the custom action template available to only the users having the subset of associated user identifiers; and the messaging system is configured to cause a user device of the action-generating user to display, to the action-generating user distinct from the template-creating user, a user interface including a plurality of selectable action generating elements for generating actions within the instant messaging communication session, wherein each of the plurality of selectable action generating elements represents an action template and wherein the plurality of selectable action generating elements includes a selectable action generating element representing the custom action template based on whether a user identifier of the action-generating user is included in the subset of the user identifiers.