What sometimes bugs me is how this term is used. Strong characters – are they ones who are dominant, in charge of the situation? The ones who have the most presence or even more superficially, the most lines?
I disagree (did you see that coming?). In my opinion, strong characters or what I prefer to say strong characterisation, is a character that has strong AND weak moments in the situations they find themselves in. The oscillation between the two merely highlight the peaks and troughs of the situation. It can help us to understand the character more and therefore the presence of him/her/it/them/et al resonates more strongly. That for me is a strong character. Regardless of who they are and what they are.
No situation (in my opinion) should be totally in favour of one side (unless maybe you’re going in for that strong didactic flavour), and most often ones orchestrated that way leave the “strong characters” vulnerable from themselves, from being in that position.
(P.S you know when a repeated phrase loses meaning after exhausting it in writing and speech? Strong character – what does that mean? Haha!)