A building will more likely collapse if it does not have any proper foundations. Similarly, the design philosophy of Triadic Game Design (TGD) needs to reside on solid building blocks, otherwise the concept will collapse as well. In this level I will elaborate on these building blocks. First I will explain what the general idea of TGD is. It is a design philosophy, for sure, but one which stresses that an "optimum" needs to be found in a design space constituted by three different worlds: Reality, Meaning, and Play. Additionally, these worlds need to be considered simultaneously and be treatedequally. The latter requires balancing the worlds which may result in different tensions, within and between two or three of the worlds. I continue by discussing each of the worlds and showing their perspective on the field of games with a meaningful purpose. From this, we clearly see that it is feasible to think of each world and that the idea makes sense. I substantiate this further by relating the notion of player and similar approaches to this framework. This level is quite a tough pill to swallow yet essential for finishing the other levels. So do not cheat or simply skip this level, but just take a big cup of coffee or tea and start reading it. Read full chapter