Questions about being a GM

I am interested in GMing my own RP, but I've never really done one so I have some questions for the GMs out there. My first question is about plot, should I already have a whole story written with a set path the RP should go on or is it better to build the start and continue the story from there? Second, how much detail should I put into the world? Finally, is there a good way to choose a winner in a fight between two players?

When it comes to writing up a whole plot, never build a one-way bridge. Players are notorious for finding ways around your obstacles in creative and unique ways. Really, as a rule of thumb when GMing, I prefer a more "seat of my pants" kind of deal -- a design an overall plot, I break it up into smaller arcs (typically three), and then let the players dictate how they reach the final goal, regardless of whether the initial goal changes or not. Basically, my credo is that planning too much digs a hole you'll feel you have to commit to lest you feel as if you wasted your time, but plan just enough that you know the overall direction of the story.

Detail is a case by case affair. Some GMs prefer oodles of rich, lavish detail in a highly elaborate world. Others prefer to fill in gaps as they arise, and otherwise keep things simple until it's necessary. Again, I'm a seat-of-pants guy, so I like to have my players contribute to the story through means of asking questions and such, because really the story -- regardless of whatever it is -- is all about the players, and I feel they should have both a sense of agency and freedom to achieve whatever it is the heroes/villains/kawaiidesu squirrel-knights have set out to accomplish in whichever way is both most befitting for their characters and (most importantly) seems the most fun.

As far as settling conflicts between characters, I don't have much experience on the freeform side of things, but I would wager it comes down to character agreement or third-party arbitration. I favor mechanics however, and prefer dice/cards/whatever to determine the ultimate victor. If Sorceress Sarah decides to get into a purely melee duel with Barbarian Bob, let the dice fall where they may; odds are pretty skewed in Bob's favor, sure, but hey, you never know. You'll need to find whichever way works best for you in that regard, I suppose.

Thanks for the advice! I am thinking of making a combat/battle arena RP like the Hunger Games. I think I know what I need to do now to get started and make it fun.

I just tossed up a guide to GMing in our Roleplayers' Codex that I would recommend looking over as well. It's not an exhaustive guide, but covers a few key factors that can help make or break a roleplay.

http://www.storytellerscircle.com/threads/6-tips-to-gming-a-successful-roleplay.940/

I'll throw a few tips out for you and anyone else who might read this.

#1: Use the KISS formula. KISS means "Keep It Simple, Stupid." Complexity is a natural byproduct of a story that goes over a long enough period of time--the harder it is for people to understand, or for you to manage, the more likely it is to fail. The simpler your initial idea, the better.

#2: Learn how plots function. Learn the difference between a premise (core idea) and a plot. Learn how to write an initiating incident.

#3: Make sure your players know exactly what role they are playing in your story. Whether that's a single character, or an entire empire they built in your world--they need to know what their role is. The GM is the focal point of any group, and if you can't direct your players, you will invariably get lost, and have confused players that don't know what to do.

#4: Be honest about your lack of experience. Be prepared for your first couple of attempts to fail spectacularly. When they do, learn from them, and see which players are willing to stick with you to try again. Few stories succeed on their first attempt.

#5: Increase the size of your vocabulary and learn about the world you live in. A writer can only create content from the depths of his or her own experiences--ergo, if you've spent your whole life obsessing over one or two TV shows and hiding in your basement, the things you create will reflect those two TV shows and nothing more. A GM is almost always tasked with world building, and that means producing history, ideology, side characters and antagonists (and occasionally protagonists), a plot and premise, and so on. The more you can learn about the real world, the more you can reflect it in your fictional works.

I've been running a small RP on another site for about just under a year now, so I feel like I have some answers in the form of my personal experience on the matter at hand, which is something that should be valuable to any person looking to become a GM.

As for the first question, there isn't really anyone who can tell you where to start and where to stop prepping your RP's storyline.

For example, myself. I've been running an RP on a different site for around just under a year now. At the beginning, I had this great, awesome idea of how it was going to pan out and be played and it was going to be super cool. However I quickly found that giving the rpers themselves some room to change the story was just as fun, if not more so. So instead of sticking to this plot I had already written out, I let the players decide their destiny for quite a lot of the storyline. However, I also know that giving RPers complete control over a storyline can lead to the death of an rp quite quickly. It's why many "open world" type rps manage to die so fast despite them being so good. The Rpers just have no feeling of direction or drive at the end of the day (granted their are exceptions).

Secondly, it is best to put as much detail into the world as you feel the situation needs. If my character is in a medical bay it is quite relevant for you as a GM to give my character information as to the different medicines and what they can do to aide my character, but perhaps going into detail as to exactly how the final ingredient of that bottle of painkillers is synthesized is unnecessary.

Finally, I like to leave fights to be decided among the players themselves. More often then not you don't have to make a choice. However should the rare need for me to make a post deciding who wins arrives, I judge purely based upon how creative the posters were in the battle. The more creative and cunning one wins.