Let's begin this level. Here we can see a scheme of the level in which we can see the starter point where the player comes in and the final point where he has to leave. This is basically what he has to do. This way, we create a scheme at a visual level and we use a legend which allows us to identify the scheme's different elements. Also, at an objectives level, we write the objectives we must accomplish in that level as we can see here. In this level the objective is leaving through the exit door, which is the final point. To do so we must open the door putting a box on a switch, door's switch, which is the green circle. To get to the box we must press the "create box" button, the box switch represented by the blue circle. The box is created in the same point, which is the "box origin" point, represented by the white square. To get the box to the switch we must turn on and use the mobile platform. In the beginning, this mobile platform is static and it will only move when we are able to redirect the laser towards the laser receptacle. To do so we must create many portals in aim to get to the box and then redirect the laser. Apart from the objectives, there appear the different events. In example, if the player falls to the water he dies and goes back to the starting point. If the player throws the box to the water, it disappears and he can create another one by pressing the box switch again. It is also important to take into account that in the level design document we don't have to explain all the mechanics. Why? Because there is a mechanics document or otherwise the design document, in which they are explained, in example there should appear that water kills. So we must simply say that there's water and this would happen, but not getting into details or repeating information that already appears in other documents. Apart from the events we work at an information level, that is, we must say which information the player has, which one he gets, etc. In this case the player learns that when he points a laser to a receptacle, mobile platforms can be activated. The player didn't know this before, it's the first time this mechanic appears in the game. We don't tell him how to get to the "create box" switch. We don't tell him how to redirect the laser towards the receptacle and we don't tell him that the platform is mobile. We must take into account all this information we don't tell him, as it is important when thinking how hard we are making the level and how will the player have to process information. To show the answer and also mark it in a schematic way, we can create two more schemes and, well, in this case the answer can be divided in two steps. The first one would be how to get to the box. To do so we would create two portals which would be here, using the yellow walls which are the ones which allow us to create portals. We put a portal here, we put the other one here and we can get to the box. This would be the first step. The next step is redirecting the laser to activate the mobile platform which lets us taking the box to the door's switch. This would be here, in the next scheme. What we do is, from the portal that was here we shoot this wall to create the portal here, so that the laser is redirected towards this receptacle. This way the mobile platform moves from left to right and allows us to get to the door's switch and the final point.