To be a DM, you need to run a game. To run a game, you need players. Where do you get them? Rather than getting into a bunch of theoretical stuff I'll talk about my current set of players and how we came together.
- Lawful Steve* - I've known Lawful Steve since right around high school. We had some mutual friends and wound up in a long-running campaign together. He later became a mainstay in some other games that I either ran or played in. We were even roommates for a while. He's a lifer. I realize some of you may not have a friend you've known since the late 80's that still plays - heck some of you may not have been alive then. Regardless, this is where you start - with good friends who either do play or have expressed some interest in playing "sometime".
*Because he plays Paladins. Or Superman. When he's not playing Paladins he plays a fighter, usually lawful good, sword and board, tank type fighter. he did play a wizard once - once. In 25 years. It was so shocking the campaign ended soon after.
- Eclectic Dave* - Dave joined us in the mid 90's during a Mechwarrior campaign and volunteered to be our merc unit's accountant and quartermaster - you don't find guys like that every day! He was a friend of Steve's and has been in almost all of my campaigns since, and we've played together in games run by other people as well. Another lifer, I expect we will be playing together for many years. He was heavily involved in the LFR and 4th edition D&D before I was ready for it and was especially helpful in those early months of getting the first game off the ground. He can also be counted on to actually read the rulebook, an increasingly rare trait.
*Because he never plays the same character twice. His first 3rd edition D&D character was a halfling wizard, then a human trip-fighter, then a swashbuckler, etc. In my first 4E campaign he played a Half-Elf Bard, in the current one he's playing a Dwarf Warden. Like I said, the only likelihood on his next character is that it will not be the same as his last character.
- Mastermind Will* - Will was a friend of Steve and Dave's who joined us back around 2000 when we were kicking off my first 3E campaign. He is typically playing in several groups so scheduling can be tricky sometimes but he's solid and always ready to play when he arrives. He usually looks for an "angle" for his character which means he's familiar with the mechanics of the game at a minimum. I'd say he's a lifer too.
*Because he always has some plan with his character and he is extremely averse to character damage. Anything he suffers better be dealt with in a hurry, but it's better never to suffer it at all. In 3E he played a Cleric in my longest campaign. In 4E he has played a Warlock and a Bow Ranger. I think that speaks for itself.
- Lady Blacksteel* - I assume the method of acquisition is fairly obvious, but in most nations this will only net you one player at a time. She came around during my final 3E campaign and got tired of watching after a session or two and rolled up a character and the rest is history. She's been a part of every game since. I'd label her a casual lifer - she does it mainly because of me but she does have some interest in it of her own- some of it is the novelty of something she was never exposed to before me, some of it is the social thing, and some of it is the competitive challenge of understanding and contributing to the pary and occasionally showing up other characters.
*Because I MARRIED her! This changes the nickname options a bit.
- Barbarian Warlord Jeremy* - Jeremy contacted me through Gamers Seeking Gamers on ENWorld a few years ago - yes those online gamer meetup things work! Well, it did until the site was hacked and destroyed, but it used to work! He was apparently a bigtime 3E player but has been completely consumed with 4E and he and Dave are our resident system experts. I'd say he's a lifer, and probably the most enthusiastic among the group during and between sessions. He's been a part of every 4E game I've run or played in and I don't expect that to change.
*Because those are the two main characters I've seen him play, both were memorable, and it sounds cool.
- Jeremy's Friend Marc* - Marc is a friend of Jeremy's who joined us last year. He plays Warcraft and was interested in D&D but had never really played it before so Jeremy talked him into it. He gets into it but he's been struggling with the schedule - family, job, gametime, WoW time - it can be difficult to integrate something new into the routine and that's what he's been trying to do. Not sure if lifer.
*Because he's Jeremy's friend, and his name is Marc, and he's the new guy.He's playing a Dwarf Cleric but this hasn't really been something to make fun of him with - yet.
So what does my little rundown above tell us? Well, find people who have friends. After you run a few games, they may invite their friends. I suppose you could call this "networking" but that sounds very buzzwordy and it's not an active process - I'm not selling my game to people and asking them to invite their friends, I just do my thing and this stuff comes up naturally. "Hey I have a friend who's interested, can they come watch next time" - "sure". We tend to do a lot more breeze-shooting than monster shooting the first hour of a session so it's easy for someone to get acquainted before we get into the abbreviations, lingo, and monty python references.
What if you don't have friends that play?
Don't forget family! Kids are great but they take years to grow into it. Extended family is a potential resource too - cousins, nephews, nieces - a gamer could be lurking nearby.
I have not tried the game store posting myself, but one of my friends that ran games used to do it and had about a 25% keep rate. By that I mean if he had 4 people interested only around 1 of them would show, play, and be someone you'd want to hang around for a game. That's not terrible I suppose, but it does disrupt the flow of a normal session when you have a totally new person walk-on to the game. There's everything from personality to hygiene to play style to mechanical familiarity to consider, and that's why I've found the friend-of-a-friend to work better- they have a "guide" who can give them the rundown of the players and the game and they have a friend at the table when it comes time to play. Still, if you're starting from scratch this is definitely an option.
Another option is the online posting for players. Gamers Seeking Gamers was the one I liked best. It's dead for now but it did work. I put up what games I was running, what our usual schedule was, and what zip code I was in, and over the course of a year or so I got 3 hits. One was Jeremy, one was a girl who showed up about 4 times then disappeared forever, and one was a guy seemed to be somewhat interested in the game and quite a bit more interested if we were 420-friendly (look it up if you're curious) which is not really my thing. So while I don't know that it's any better than a store posting it is easy to update and easy to access at weird times of the day. There are various rpg meetup and gamer meetup and locator groups but none of them seem to have the size that the ENWorld one did - plus I was running a lot of D&D and that's a pretty big crossroads for D&D. Another suggestion: the main online forums for the game of your choice - it couldn't hurt.
As far as playing online I'm not much help - I've tried it twice and both game fell through before anything got going, which soured me on the whole thing. Plus I have enough to manage juggling the face to face games. I know there are people making it work though.
In a way this can be the most difficult part of being a DM - starting! Especially starting cold. I've been fortunate enough to be part of an active group of players for the last 30 years, with some turnover but in general with more new players joining our extended circle of friends than leaving it. Not everyone has that good fortune. For those I will say two things:
1) Find a local store. Go there. Play stuff, even non-RPG's (40K, Magic, etc). This will lead to meeting other people who play games and might plug you in to an existing group or give you some candidates to start your own.
2) Keep trying - it's worth it.
That's all for now!