I have a love/hate relationship with the 70s. I grew up in the 70s and have good memories of them. Loved classic rock, hated disco. Loved the new age occult revival, could have cared less about some of the other stuff. I grew up then, but consider myself a child of the 80s.
Damnation Decade though is the pure raw distillation of everything 70s, good and bad, into one awesome game. It is a historical game, in the same way Ghosts of Albion is about 1839. Damnation Decade takes a wrong turn in 1974 down a dead end. The world is sort of like ours, yet also very different in some key respects. Damnation Decade is also quite possibly the one RPG product to ever tacitly or implicitly illustrate that things under President Ford could have been a lot worse that what we really got. Reading through Damnation Decade is at the same time a trip down memory lane and an exercise in identifying puns and analogues to our real world. Green Ronin: did we really need a world where folk singer Edmund Fitzgerald sings about the Wreck of the Gordon Lightfoot? But I guess you are forgiven by giving us the first RPG product to feature a real Fantasy Island.
It reminds me of another great game, Solid!, which is also about the 70's. If Solid! is Parliament, then Damnation Decade is Grand Funk Railroad. Damnation Decade though gives something that Solid lacks; memorable NPCs. Sure if you can get past that most of them are amalgams of 4 or 5 70s figures, for example Humboldt Suede is not just a bad Hugh Heffner rip-off, he is part Hugh Hefner, Bob Guccione AND the Son of Satan. Though some are original enough to be useful outside the 70s atmosphere; Theramin Hunker for example could work well (maybe even better) in 21st Century games full of conspiracies.
Damnation Decade works great as a d20 game AND it has a True20 appendix that might even be better.
[5 of 5 Stars!]