Other answers state how to pass in the command line variables but not how to access them, so if you do:
--extra-vars "version=1.23.45 other_variable=foo"
In your yml file you assign these to scoped ansible variables by doing something like:
vars:
my_version: "{{ version }}"
my_other_variable: {{ other_variable }}
An alternative to using command line args is to utilise environmental variables that are already defined within your session, you can reference these within your ansible yml files like this:
vars:
my_version: "{{ lookup('env', 'version') }}"
my_other_variable: {{ lookup('env', 'other_variable') }}