I like to learn through playing with things, so here is a little project showing how a tile based level can be constructed using a scratch list and a set of sprite costumes. The formula at the bottom shows how to know which row in the 'Level' list represents each cell of the level grid. Have a click around, enter values, and see what happens! There are many benefits to this approach of creating levels, one of which is that you can script enemies that are aware of their surrounding tiles even when off screen. So... does this help anyone...? Shall I go on...? For those who want to know the inverse of that equation. Given an index value, then: x = (index-1) mod (Level Width) y = floor( (index-1) / (Level Width) ) The mod operator stands for the modulus, and it gives you the remainder after dividing the left hand side with the right... It is dead useful when working with tile based games :) It goes without saying: all credit to mojang for the minecraft blocks!