I went paintballing on Saturday too. It's great fun, I hardly got hit
Once me and my friend were hid behind a van, trying to get the guys behind it. One of the green team (we were back) came behind us and shouted surrender (it's a rule) and we spun around. I panicked and shot the guy. Realising what I done I shouted "Oh s***!" and then raised my hand and shouted surrender, cause I knew he would totally blast me.
It does hurt, and sometimes it does bruise.
Ours was outday and I got soaking and muddy as. One "round", called "Trenches" meant running knee to waist high in water through trenches. Great fun, but costly. Altogether I spent £6 on entry, £40 on paintballs, £5 on snacks I brought in my bag!