Uller
Adventurer
Sorry for noob question but what's a session 0?
Typically we DMs call the first time a group gets together "Session 0". It is called that because no actually game play is planned for that game session. It is used to do some house keeping like:
Describe the basics of the setting, general thrust of the campaign and set guidelines and expectations for character creation.
- Don't go crazy with the setting details. Keep it vague enough that there is room to fill in things with the imaginations of your players. For instance, if a player announces he is a noble and a knight in a declining religious order, leave room for his noble family, their estate, connections and his order and its history.
- Guidelines for character creation can be what sources can be used (I use "PHB plus one other source with approval from me"), what races and classes are acceptable, etc.
Create characters as a group
This way, your players can work together to make a group of PCs of characters that WANT to adventure and WANT to work together. Either give them the reason in advance (you are all captured by Drow and trying to survive/escape) or you can let them decide.
Agree on house rules and set expectations for play
Every group has house rules. I keep them to a minimum (no more than what can fit on one typed page). Some groups want pure RAW but if you've been playing together and a particular rule has caused confusion, now is the time to set some expectations on how you will rule on it. Stealth is a big one...if I'm playing a Rogue, I want to know how the DM will generally rule on Stealth checks and the like before I agree to play the rogue. Or if a player is counting on a mount, how will the DM rule on mounted combat rules. You can't cover every thing here but you can hit the highlights.
.Also, some groups are playing as an excuse to gather for pizza and beer and exchanging pop movie quotes inspired by what is happening in the game...others are there to play a game where everyone is playing optimized PCs and paying attention with laser focus. Others find funny names and fart jokes distracting, others are interested in collective story telling by serious method actors who always speak in character...Session 0 is where you establish what you and the group consider acceptable (and FUN).
As for your original question: I like to start with action or a scene reminiscent of Indiana Jones Raiders of the Lost Ark or Temple of Doom...why anyone is there, it is up to the players to fill in. To me, it is far more fun (and gives a lot more flexibility) than playing through awkward introductory encounters.