Image by mediafury via FlickrThe plan, following my jaunt into free-flowing GammaWorld goodness, is to structure my game-mastering so that:

• There is no "Adventure Path Railroad" my players have to follow, but there is still structure and plot.
• The heroes can choose their sides and actions without having to worry about derailing the abovementioned plot-train.
• I have minimal prep for each adventure / story arc, and can easily take the game wherever the players choose.
• We can roll dice, have fun, and tell stories without anyone having to write (or, for that matter, READ) pages of story and fluff that may not end up being relevant to the story anyway.  See points 1 and 2.

To allow for all this flexibility, and as I'm opting for a fantasy setting,  I'm tempted to go with either Pathfinder (which we all know and love) with an Epic 6 flavour, or DARPG (which seems pretty cool, and easy to run on the fly).  Steps to world domination are:

1. Draw, build, or find a place for the PCs to call home enough to care about (or care about enough to call home) with plenty going on and its own factions and agendas... this may end up being an area - as it was for the GammaWorld campaign - or more likely a city.  I enjoyed working with the central city of my 4e campaign.
2. Set up the relevant factions, with their key agendas and NPCs (in a similar way to the worldbuilding set out in the excellent Dresden Files RPG "Your Story" book, these are the hooks to hang everything else on as we play) for a little local colour.
3. Create... three? four? simple story arcs, with set piece encounters sketched out for when it matters.  Preferably playable from both sides, and with ready-to-roll NPCs to drop in at multiple/relevant CRs.
4. PLAY!  Add more of the above as and when one of the players (classing myself as a player, which all DMs should) sows a seed as we play.

Wish me luck!  Any tips would be greatly appreciated...