Variables can be of different types. Text variables have a string of text as content and numeric variables have numbers as content. You can’t add up text to numbers and vice versa.
If you do *create strength_1 "something inside quotes" the value of strength would be whatever you put inside quotes.
If you do *create strength_2 5 the value of strength would be numeric 5
You can’t compare a text value to a numeric value, like *if strength_1 = 0 cause "something inside quotes" isn’t a number.
Your question is already answered in your last post.