There's a big, bold cosmos out there.
We've always suspected that we aren't alone in the universe and while humanity is often wrong about a lot of things in this instance we're oh so right. Aliens have been messing around with Earth here and there for the past few thousand years and this can be seen everywhere from the Easter Island heads to the fact that there are now a bunch of Aztecs with their own space empire. Also, Thetans. Thetans everywhere.
Things really started hotting up in WW2 when the individualism-championing Greys and the stability-seeking Cherraspids decided to get their hands dirty in our politics, secretly backing the Allies and Axis respectively and giving us the secret of space travel. It's now the 1950s and humanity is making its first steps towards the stars, if only to take down that secret Nazi base on the moon. Oh, thanks to them we can do time travel and alternate dimensions, so if throwing a spanner into the works of intergalactic politics isn't enough for you then why not meddle in the time stream or multiverse as well?
Combining satirical, light-hearted 50s sci-fi with rules-light, diceless and narrative driven rules, Dinosaurs...In Spaaace! is a fleshing out, settingwise, of Greg Stolze's free rpg In Spaaace!, which can be found on the same page as the above link. It's melting pot of wacky sci-fi, namely inscrutable aliens with offbeat agendas, time travel, Nazis and of course dinosaurs. The rules of the game take up about 15 pages (with the odd sidebar or two elsewhere), with the rest dedicated to the cosmos, its inhabitants, the consequences and history of time travel and a T-Rex ranch in our asteroid belt. You know, the usual.
As well as the familiar concepts, you've also got a whole bunch of really cool, unique ideas. The Cherraspids, the other major alien race besides the Greys, are the stand-outs. They're sort of buglike and semi-inhabit multiple dimensions at the same time. They also have limited precognition, thanks to their ability to perceive multiple outcomes of every choice they make. Unfortunately this leads to them being incredibly indecisive and valuing stability and conformity in all things, which is why they backed the Nazis. A fair chunk of the book is devoted to explaining how they work but it's an awesome concept. The Sky Aztecs, the descendants of Aztec priests and kings who beat up the peaceful aliens who happened across their empire millennia ago and co-opted their tech to extend their reach to the stars above, are another of my favourites.
Dinosaurs makes use of the Token Effort system, a bidding resolution mechanic. Each player and the GM has a certain number of Plot Points. Whenever you get in a conflict or want to alter the facts of a scenario, you bid tokens. Whoever bids the most wins and gets to determine the outcome, though the GM may require a minimum Ante depending on the plausibility of the scenario. The loser, GM or player, then takes one token from the winner, as well as the ante being paid to the GM if the player won (in the case of a tie, the player gets to narrate but the GM gets all the tokens used). There's also Rule Zero, which is when somebody, player or GM, makes you laugh, you owe that person a token. Humour and light-hearted antics are the name of the game after all.
I have one quibble with this game's setting. It tackles all of the best alien conspiracy theories, from the Easter Island heads to the Greys to Scientology to Aztec 'sky gods'. Yet, no reptoids or anything similar. Look, I understand too many cooks can spoil the broth, but what kind of xenoicious (That's my word, by the way, you can't have it) world do we live in where sinister, cold-blooded shapeshifters from outer space aren't trying to infiltrate our governments? For shame, Mr Stolze, for shame.
Step 1) Distribute Points Among Traits
Characters in Dinosaurs have exactly one stat, Traits. A trait, which can go no higher than 5, allows you to increase your bid for free when applied to a relevant contest. If I have the trait Cryptographer 3 and I have to decipher some ancient alien inscriptions found in a lost temple I automatically have a bid equal to 3 and can add tokens if I want to be super-sure of success.
I get 4 points to spread across traits, with no starting trait higher than 3 points. And you know what? I'm going to create Elvis Presley.
OK, he's not quite our Elvis Presley. See, the idea I have here is that in an escapade involving aliens from the future a whole bunch of Elvises from alternate universes were brought here and this particular one decided to stay on our Earth to give us a hand. This version of Elvis decided to become a fighter pilot instead of the King and joined his Earth's version of Project MAGNIFICAT (America's primary defense against space threats).
The first trait I'm going to create is Pilot Starships which I'm going to sink 3 points into. If you need a man to get you to Tismo and do a barrel roll on the way then Captain Presley is your man. The second trait I'm going to make is He's Still Elvis and it's going to be a Broad trait. Whereas average traits cover one specific thing, broad traits can cover three general and more broadly useful areas. In this case, despite the fact he's from another timeline, this Elvis can still sing like a leather-jacketed angel, perform mad kung-fu and eat more deep fried mars bars or what have you than a T-Rex on steroids.
That's pretty much it. I might get some Temporary Traits from stuff like Gear later on, but I'm ready to hit the stars.
The Finished Product
Captain Elvis Presley
He's Still Elvis 1
Pilot Starships 3
How I'd Run It
I actually kind of want to run a 'League of Extraordinary Elvises' game now, I think it would make an awesome one-shot. The real question isn't why aliens would gather the King from acorss the multiverse (I have about three different plots in mind for that), it's whether a goatee would suit Evil Elvis or should he have a Fu Manchu or something?
One other thing that really grabbed me as an awesome basis for a campaign is the description of Grey Haven, a possible future Earth where the Grey's plans for us have been fully realised. Thanks to mass advancements in communication, transport and other technological areas in 2151 we've become an overpopulated transhumanist paradise. I envision it as a slightly more optimistic Transmetropolitan. Its focus on gene splicing, one of my favourite aspects of trasnhumanist sci-fi, only endears it to me more. While you could do a few things with such a setting a police procedural game set in a world where the definitions of what is human are blurred at best could be great for a short campaign.