The nice thing about Amber Diceless is that it's really well made for forum based RP. Here's the bit that loses a lot of system players.
Amber runs entirely on GM fiat. If you don't trust your GM to treat you fairly and impartially, don't play, it's not worth the hassle. The only game mechanics happen at the very beginning of the game, during character creation. There are four stats:
Warfare: Your character's ability to fight with weapons and wage war, be it with swords, machine guns, or platoons. Benedict is widely acknowledged to be the Prince with the highest warfare in the Chronicles.
Strength: Your character's raw strength and ability in hand to hand combat. A high strength character is generally better at taking a hit than a low strength character. Gerard was the paragon of strength in the Chronicles.
Endurance: How long it takes you to tire and how quickly you recover from injury. Corwin, the protagonist of the first Chronicle was the paragon of endurance. He regenerated his eyes after they were burned out of his skull. That's badass. Gamewise, so long as an Endurance based character can take their time and fight defensively, they can wear out their attackers.
Psyche: A measure of a character's mental strength and gift for sorcery/higher arts. Psyche can be very potent, because if you can make a mental link with another character, say by spell, Trump, or even intense, prolonged eye contact, you can, with a sufficient Psyche advantage, do horrible things to them.
Now, all the players get a set number of points as determined by the GM. They divide those points, generally by auction, but some GMs just have PCs spend their points however they like. After your points are assigned, you're Ranked, and your ranking is what really matters. The points are kept for reference, but Rank is the real measuring stick.
If you know another character outranks you in Warfare, be very careful about getting into a sword fight with them. Of course, combat is very narrative. You don't have hit points. Instead, the GM gives you feedback. Very, very rarely will a character get one shotted, and then only if you've made a serious tactical blunder. Imagine Brand picking a fist fight with Gerard, and you have an idea of what it'll take for someone to get taken out without some warning things are going sour. Generally what happens is you pose what you're attempting, and the GM give you feedback, and you decide how to continue from there.
Corinthi frowns at the peasant who just spilled a drink in his lap. While the peasant was almost 7 foot tall and built like a tank, Corinthi was a bloody prince of Amber, and was three kinds of drunk. He grabs the peasant by the shoulder and smashes a bottle over his head.
The bottle shatters in a satisfying manner, sharps of glass and beer showering down over the giant. Who slowly turns toward you with an 'annoyed' expression. Pain explodes across the side of Corinthi's face as it feels like someone hit him in the cheek with a sledgehammer. The prince staggers back against the bar, head ringing and mouth filling with blood. He hadn't even seen the punch coming and is nearly certain he can't take many more hits like that.
'Holy shit' warred with 'Oww' for the dominant thought in Corinthi's mind as he reeled from the blow. Who the hell had he picked a fight with, Gerard? He could draw his blade, but he was already seeing double and wasn't entirely certain he could stab his assailant before being beaten to death. Perhaps discretion was the better part of valor in this situation.
No dice, just judgment based on the information the GM provides. Which means Amber /needs/ a good descriptive GM or it's unworkable.