When running a Mass Effect RP it would be all too simple to simply sit back, relax and bring in the old tried-and-tested "Free Trader" campaign model, where the characters are a pick-n-mix of races and cultures united by the simple goal of making money.
Yet this simple concept has always had it's flaws. For example, how many merchant ships plying the seas of the modern world regularly abandon contracts to go haring off on some wild-goose chase in search of adventure? Not many. Factor in the complete lack of over-riding campaign direction in simply flying around trying to sells tuff and you've lost my interest completely. Yeah, that's right. I'm that guy who hated Elite back in high-school.
There's nothing wrong with a free-trader style game, it's just not my thing. Yet despite that, Sand-box style play is my favorite type of campaign. However, for me there has to be a decent, over-riding reason for the characters to work and fight together. In my soon to begin OSRIC "Expeditionary campaign [link] the twenty odd characters have all been ship-wrecked on a strange island.
Luckily, in the Mass Effect universe there are plenty of options to explain the existence of a (traditionaly) mixed-race, mixed-background adventuring party.All of which fit the themes and tropes of the Mass Effect universe.
Probably the most obvious choice. One or more members of the party are Spectres. The rest are his agents. This model is somewhat similar to the "Throne Agents" model of the Inquisitor RPG, and lends itself well to a Mass Effect roleplaying campaign. The Spectre might be an actual member of the group (like Shepherd and his crew), or an NPC directing the group from the shadows of a different world or even a space craft (like the Illusive Man and Cerberus. The only real issue with having a Spectre as a PC is the very real risk of abuse. What's to stop a Spectre from simply requisitioning everything he needs, from an experimental ship to an entire army (or armada)? The answer is to either have the team working under circumstances that precludes having the Spectre blow his cover (still risky; if things go wrong her can still call in the big guns) or have the Spectre operate outside Council space. Outside council space (say beyond a newly re-opened relay) not only won't his Spectre status serve to impress anyone save other ex-pats from council space, the locals probably won't even know what a Spectre is.
This latter option is the direction my campaign will be taking, with a PC Spectre and his crew pursuing a wanted war-criminal beyond the bounds of Council Space.
The Cerberus Model:
Cerberus has already shown itself willing to work with non-humans, and most of the Cerberus personnel encountered in ME2 lack the xeno-phobia the organisation is supposedly famous for. Of course, it could just be that the Illusive Man was smart enough to pick the least racist members of his group to work with Shepherd. But even so, justification exists for a humano-centric team furthering this groups goals with a few alien allies or mercenaries in tow. Such a campaign model has a wealth of RP opportunities. A Spectre, for example, goes where he is needed. But it wouldn't be too hard to establish a Cerberus team working out of a particular station or planet if you wanted to spend more time establishing certain locations and local NPC's.
Finally, Cerberus might be the only "militant private interest group" we really know about thus far, but that's not to say the other races don't have a similar organisation (perhaps with the goal of acquiring a council place for the member races in question) working for them.
The Merc Model:
The players are all mercs working for a group such as the Blood Pack, Blue Suns or Eclipse. The main difficulty here being that mercs rarely get the chance to further their own interests or chase up personal quests. They go where the money is. This style of campaign has a lot of pros's, but tends to limit player choice to picking what contract to accept (if they happen to be senior members of a large group or the only members of a small team) and missions ultimately tend to have a lack of variety. The "mission of the week" syndrome tends to rear it's ugly head all too quickly using this campaign style. This sort of campaign is very apt for an episodic play style, but if that's not what your group is after the Merc template can very quickly become limiting. One way around this is to use long-term or open-target contracts rather than one-mission, specific-target contracts . These offer the PC's a great deal more latitude in determining how (and when) to fulfill the mission.
For example, a long-term contract to "de-stabilise Synapse corporation activities on this world to facilitate a buy-out of Corporate assets" offers a lot more lee-way and room for initiative and character-growth than a short-term: " Attack this particular synapse factory and put it out of action." The first contract lets the characters choose other options than a straight up fire-fight to meet their goals and also gives the players a sense of accomplishment. They can see the gradual effects that their activities are having on the game world. The second contract would have railroaded them into a fight, more or less forcing them off-planet immediately afterwords and preventing them from a glimpse of the big picture.
The Corsair/Asari Commando/Special Tasks Group Model:
We know that the various council races all have special military and para-military units they use to take on and overcome challenges that conventional military or espionage elements could not handle. The only real difference between these groups and Spectres is, as far as I can see, that Spectres have more legal power, more-back up and work for the benefit of the galaxy as a whole (or at least the Citadel races). Whereas these groups work on behalf of their own governments, albeit occasionally being assigned other tasks at the request of the Citadel Council, much like the STG task force on Vermire.
This sort of campaign has many of the same pros-and-cons as the Merc format above, save that the PC's at least know their employer isn't going to screw-them behind their backs (in the military, when you're "employer" is screwing you, they at least have the decency to do it to your face and make it sound like they're actually doing you a favour). However, the different groups listed above each seem to have their own flavour and way of doing things. The STG seems most like a traditional Special Forces unit, albiet one with scientists and the like. The Asari Commando units on the other hand, have a "tribal" command structure and tend to carry out espionage and strike missions. The Corsairs, it seems (from the vague references made by Jacob in Mass Effect 2) work more like privateers, posing as private citizens but secretly in the pay of the Earth government.
Unlike the other Special Forces options, the Corsairs option could conceivably include characters from other races and distinctly non-military backgrounds, perhaps unaware of who their captain and senior officers really work for.
Out of all the listed options in this section, the Corsair model is probably the most playable. Using this model, the characters will be able to pursue their own goals, (including trade, if the party is in to that sort of thing) as well as performing secret missions on behalf of the Alliance Fleet.
Note: All images copyright BioWare and EA