That means one of these four components is a mismatched datatype:
Worksheets("battle").Range("b6").Offset(0, number).Value
Round(19 * Rnd)
1
CInt(initiative_range.Value)
Or, CInt(initiative_range.Value)
can't be converted to an Integer.
Or, number
is not a number
Why don't you go into debug mode and inspect each of these components and work it out.
It's probably the CInt
part.