**2.2 Didactical structural templates**

The so-called didactical structural templates (DSTs) have been introduced in [30] and extended in [20]. As described, the DSTs are based on the IMS learning design (IMS-LD) [31] and represent the didactical structure of a course and cannot only be used as a didactical structure for creating courses. The DSTs can also be used as a didactical structure for a hybrid environment existing of a "classical" course with integrated applied gaming content, just like a pedagogical structure for the applied game, which can be a web-based computer game. Therefore, one DST can have different implementations. The advantage of this approach is that learners will be able to switch between different implementations of one DST whenever they want to. They have got the same learning progress as if they had used only one specific implementation of this DST. This means that if learners like gaming, they can use the applied gaming implementation to work on the learning content. For example, suppose it is easier for the learners to answer the self-test or the final test—to stay in the exemplary stated pedagogical structure of a course for example, multiple-choice quizzes. In that case, they can switch to a course within an LMS to answer the questions. Therefore, the DSTs have the following hierarchical structure:

Method: There are many different ways a person can learn or teach. Each learning method is a sequence of learning processes.

Play: It is a key part of the learning design, representing a teaching-learning process. Like a theatrical play with a sequence of acts, when an act is completed, the next act begins until the completion condition is met.

Act: An act represents a series of simultaneous activities and activity structures.

Activity: It is one of the core elements of learning design, which relates to many learning environments.

Activity structure: Activities can be combined into an activity structure with sequence mechanisms or freely selectable structuring. To access the DSTs, we have provided a RESTful API described in [32]. With the DSTs, we can provide the didactical structure of learning content in a standard, conform way.
