Rename your Event Sheet to MainCode
Create a group to store all the various functions needed to make the game work - call it FUNCTIONS
We need a global variable to store a list of the four basic known elements.
We need a function which will update the list and replace locks for playable elements like fire, water etc.
The built-in System Expression - find works as follows:
Find the first index within src that text occurs, else returns -1.
find is case-insensitive, and findCase is case-sensitive.
If the value returned from the method IS NOT EQUAL TO -1, then we know that the element IS in the list.
Record the starting positions of each Element to local variables and refresh the list of discoveries