Hi,

is it possible to define a variable in the beginning with the value "0" and then after each question add "1" to this variable?

You could put an equation type question in the first group with a value of 0 and then increment it with equation questions in every subsequent group, using the assignment operator.

www.limesurvey.org/manual/Expression_Man..._Assignment_Operator

I don't like to use a Equation question type for the counter, prefer an numeric questioin type with default value 0

Why?

Because, for example : if you have index activated : Equation can be resetted when submit.
In fact Equation is resetted each time "step" is done (move previous for example).

With a default value : it's set only if it's null or not set.

I think reload survey can reset the value too (to be tested).