Saying "yes" to your players can be hard. What I mean by "saying yes" is to allow players to do what they want.
My players currently have a party with a Minotaur in it. A Minotaur! A creature of legend!
My gut reaction to having a Minotaur walking around in my adventure is that it doesn't really belong. I do plan some city-based adventures, and my idea of Prolia is modeled after a weird hybrid of Norse and Celtic coastal society. Traditional, longhouses, Jarls, fishing, and rural. Actually seeing a Minotaur walking through town would certainly be disruptive!
When the player of the Minotaur and I were originally talking bout the races in 4th edition, he was slightly distressed that the half-orc was gone. He's a player that enjoys playing the big, strong and as monstrous as you can get, within the rules. If he plays Shadowrun, he'll be a Troll. In Feng-Shui, probably a "Monster". In Champions, a mutant brick of some sort. It's just him. It's what he likes.
The question is, whether having a Minotaur around really has to be disruptive. Prolia is certainly not a real world. It's whatever I decide it is. My original vision of Prolia didn't have Minotaurs as an accepted part of town life. Minotaurs are monsters! But is my original vision really all that different, if I change things a bit and say that, Minotaurs don't really distress people that much? What if there were some encouraging stories of a Minotaur hero from ages ago. Maybe Prolians would be afraid, uneasy, and initially distrustful of a Minotaur walking around, but maybe most Prolians do have the ability to accept him once he proves himself as an ally.
The careful planner in me makes me want to say "no" to suggestions that I don't expect. To say "no" to things that are not what I envisioned. To say no, when I'm not sure about something. i don't want players to run amok in my beloved campaign. I want things to proceed as planned. To methodically and orderly proceed through my story and do never surprise me with a curve ball that shakes up my world.
I said, "yes". And with that one word, his eyes lit up like a kid with candy. It's simple; fun is good. The truth is, that this particular player is in love with the idea of playing a Minotaur. I know he's having a blast doing his brutish monster thing, and the end result is that Minotaur hasn't upset my plans.
Now if my player was just pushing for a Str/Con combo fighter and like the ability that minotaurs with large weapons, it may have worked out differently. I'd be willing to give somebody the mechanics of a Minotaur without actually being one if that's what they really wanted. So, you're a big human of dubious parentage, possibly a monster in your genetic background, and you have all the stats and abilities of a Minotaur. It's their character and as long as they are not raining on anyone's parade, and they aren't messing with my plans, they can do *whatever* makes them happy.
So even with a Minotaur PC, everything is just fine in Prolia. My plot is intact. A few new role-playing opportunities have arisen in dealing with the townsfolk, but it's nothing that the party and the towns can't handle.
My instincts to say "no" are dead wrong. I don't really want the things I think I do. I'm game mastering for my players because it's the players that give life to my campaign. The unexpected suggestions, the requests that I'm worried about, the danger to my plans are what brings a campaign to life. It's what makes the game interesting to me. If I wanted things to go *exactly* as I planned, I'd be playing alone. I could control *everything*... and there would be no point. No fun. Nothing interesting for me.
I must constantly push myself to allow players to play what they want. When I'm not sure, or when I'm caught by surprise by a suggestion, I shall say "Yes" unless there's a good reason not to. I shall roll with the punches. I shall use the players' ideas to make the game more enjoyable for everyone.