It will always make a mix of all the conditions, and if they are all TRUE, then the reaction(s) will be executed. You can also put more than one condition just by putting the squares next to the others on the same side of the arrow. If there's no conditions, the program will automatically execute the reaction. There's also some sensors that can be use, such as 'bump', 'in water' or 'tap'. But the colors, textures and some prefab actions (for the action blocks) can be put in there. Don't panic, that's totally normal and logical: You cannot put another 3D shape for condition! So, all kind of blocks cannot be use for programmation.
If you played a little bit with the programmation panel, you will notice that there are some 'GUI squares' (the squares in the inventory) that cannot be placed in the programmation box. That's that simple, but you will noticed that it can become VERY complex if you make bigger worlds. So if we mix all this up, it make 'if my block is red, then explode', or in the Blocksworld language, 'red does explode'. The other side, the THEN, are used for reactions, like '.then explode'. The IF section (on left) is used for a condition, like 'if this block is red.'.
This arrow split the programmation into 2 columns: The IF and the THEN. When you put a block on the map, (by dragging it out of the inventory,) you will see a little box appear with a arrow in that will be write 'does' on.
