A Dirty World (Cubicle 7, 2008)
This is a small gem from Greg Stoltz (I suspect most known for his White Wolf work, but also developed the One Roll Engine). It barely defines it's own setting, however, contenting itself with two pages of opening fiction and one on defining Film Noir. It's a good description though, and it's complemented by the game examples. Most people understand film noir though, so the only element I want to include here is that it's about compromise (my definition not A Dirty World's). Getting the job may involve compromises with shady characters; getting the right thing done may involve compromising yourself.
Stoltze uses the One Roll Engine (looking for matching d10s), although it's really not that critical for these rules. While it feels wrong, there are actually 50% odds of a match at 4 dice, 70% at 5 and 85% at 6. For the purposes of ADW, he stripped out a lot of complications that I found in Godlike (not additional rules, but complications to the main rules) - I like this more streamlined version, but if you already use the Engine it's probably worth sticking to the version you know.
The gem I mentioned though is the choice of stats and how they work.
Characters have 3 pairs of Identities, each with 2 pairs of Qualities all rated 0-5. More than 2 of any stat reduces the maximum of its paired Identity or Quality. Dice pools are Quality + one of its pair of Identities. So far not unusual. The clever bit is how they work. Firstly they are (mostly) good choices that really do appear to balance each other which is important because of how pairs work with each other. Because your Qualities change (they're the 'small' numbers).
At the end of any scene you can slide a pair of Qualities one way or the other (reduce one to increase the other). This could be because you have changed, to regain a bit of self lost previously or to steel yourself for what lies ahead. Some situations let you improve a Quality after a scene. Which seems nice, except for how easily they can be lost. Given the right story, any Quality can attack any Quality of an opponent (so Corruption can sap Courage, Wrath can beat Selfishness out of someone. Most of the time you will be sliding the target Quality to its matching pair, but if you're doing 'well' you can just remove it. It's worth noting that your Qualities (and to a lesser extent your Identities) don't define your character, just what you feel capable of at a given point.
What this means is that there is a cost to confrontation. If someone is telling you to back down, you have to decide how much you are prepared to risk before obeying. Gun fights are not to the death, but until someone decides they don't want to risk any more Vigor. When you are shouting at the bouncer to let you in, he probably doesn't care enough to risk his Endurance until his boss comes down and they can team up against you. It's a system which lets characters do what they want up to the risk they are prepared to take.
The choice of Identities and Qualities is mostly very well chosen. Patience (long-term) vs Cunning, Vigor vs Grace, Understanding vs Persuasion. Wrath (violence against those weaker than you) vs Courage (when fighting against the odds), Purity vs Corruption etc. Some names are awkward and non-intuitive ("Demonstration"), while I am not sure that Honesty/Deceit is that different to the latter. But that's nothing that can't be house-ruled.
A Dirty World is an elegant 70 pages of a system to help you convey the compromising world of film noir. I know there are those who claim you don't need mechanics for roleplaying and film noir is ripe for this but for those who want to retain the 'game' aspect of an rpg, the wrong rules can spoil the mood. These on the other hand keep your mind focussed on what's important - your character and their personal dilemnas.
For fun, there is also a quick plot-generator. It's well thought out but due to the nature of the One Roll Engine does have a tendency to throw lots of petty issues at you - regular use will see a lot of divorce, short cons and "amorous badgering". Not quite as fun as the Hellcats and Hockeysticks plot generator.
There is little intrinsically bad about what the book gives you, but it's not particularly long. There is no background, no metaplot, no world-building of any kind. But that's what you get for something set in the real world without any supernatural presence. It's assumed if you are running a film noir game, that you have watched enough films to be able to grok the setting by yourself. And it's not like there aren't examples in the book to remind you of the mood.
I'm pretty much down to the choice of Identities and Qualities here, as above. I would like to run it first before I give any firm statements on good and bad. There is also the quality of the One Roll Engine - has anyone reading this tried it? Does it work?
Ideas: 7 - I added an extra point for the plot-generator