This is something that's been bothering me for a while.
We play volleyball socially and the team is mixed gender, aged 20 - 50+, mixed level (from complete beginners to two advanced players who join us occasionally).
I've been playing for almost two years now. I would rate myself above beginner level. But because of weight-lifting and martial arts, I have developed strong arms and can deliver the fastest serves in the team (although my spikes are weak due to bad technique, working on that). But I cannot do jump serves.
We have played against some professional players, and we got some easy points from my serves. Again, I'm not trying to show off or anything, I just want to know if I'm doing something wrong.
My question is: is it ethical to serve really hard? Is there unwritten or maybe written rule?
I do serve weaker and higher when I target a beginner in the opposite team to avoid injuries. (but that's something we were debating as well).