Dming two parties in same world

[With a box]

I was a bit tired to make story advence in background, so I invented a trick:
Put two diffrent group in same world, and roll them by turns(one is monday , and the other is wizarday) in short, each group group make other group's plot
Problem is.. what should i do if they meet?
And i need any advice about this idea

[Segev]

If they meet, you end the current session and invite the group at this session to the next one for the other group. Then you introduce the other group to the fact that their characters are encountering this other group's characters, and let them interact.

[jjcrpntr]

That could be fun if one group of players was an evil campaign and they were the baddies the other "good" PC's were hunting down. Get everyone together for the climatic showdown to see which party can tpk the other fastest.

For your original question, sorry no idea can't help you. But this sounds like something that could be fun.

[Kantolin]

This is a really fun idea! I've done this several times.

A couple headaches to look out for:

- Time differences. This one can be killer - it's very neat to have party B incidentally destroy a silver mine, and then party A goes to that silver mine to do things... but things can get wonky when one group is a few days ahead of the other, and that's functionally guaranteed to happen eventually due to either one group doing more traveling than the other (unless you're gonna delay people from 'you go to the next town'), people being sick and missing game, or just 'wow this run took a lot longer than I figured'. Try to use extra timeskips to keep people as close together as possible.

- Information beforehand. If an endgoal is PvP, or even just 'PvP is acceptable' (Such as one group being evil and the other good), make sure the players know about this ahead of time. PvP between people of equivalent levels is usually extraordinarily lethal - if that isn't what people are expecting it may rub them the wrong way. Relatedly, you'll want to watch out for optimization differences amongst your groups - when the sword and board fighter goes up against the power attacking barbarian and the former is squished in the first round...

...which will likely lead to an optimization race in the future (or immediately!), and arms races usually means everyone loses. Minor things will also be in conflict - if one group can teleport and the other can't (or even if one group can teleport and the other can't /yet/ - maybe their arcanist is a sorceror vs a wizard, or a theurge vs a pure), that group will have a major advantage in 'doing things'. This may also cause undue annoyance if someone wants to be a warmage instead of a wizard. Or a monk instead of a swordsage, or a swordsage instead of a druid, or a druid instead of a planar shepard, or...

Alternately, you could maintain a 'No PvP' type of setting and just request/require the players all adhere to that social contract.

This can definitely make a world more organic feeling, however - it may help to have a good 'newspaper' system so people become aware of major things that are happening.

[XmonkTad]

I have a DM that is attempting to start just such a game. The way he has it divided up is:

Party 1: The "normal" party. This is a regular good-aligned, dungeon-crawling, world-saving, party of 4 people with their game being run at the table. There is a great deal of conflict in this world, and these guys are trying to sort it all out. I don't know any details about them because

Party 2: My party. Started out as just me running a CE Factotum going into Fortune's Friend, but later another friend joined as a gestalt dread necro//monk skeleton. It's my character's job to get as rich as possible (whisper gnome that worships The Glutton from RoS) by doing everything from using extract drug to corrupt small villages to run weapons to warring nations. We play over Skype (the reason for the split).

The world this is happening in is large, and detailed enough so that there is stuff to do that isn't pvp. Furthermore I have no idea who party A is, and what events are their doing vs simply events of the world unfolding. I'm not a second "rival" party (though you could run it that way), but the group's goals are so opposed to one another that there is no way for them to be on the same side (read: no reason to merge parties).