The Amber Diceless Role-Playing Game (Wikipedia) I bought the game and its companion book, Shadow Knight back in the 1990s and it’s held a place on my RPG bucket list ever since.
I loved the idea of the diceless mechanic, from the attribute auction where players strategically vied for the best character attributes to how the game master used a character’s “Good Stuff” (points left over from character creation) and “Bad Stuff” (negative points, also from character creation) to drive conflict and outcomes in the game.
I’d like to play a convention game or two of Amber DRPG so I could see the rules in action, and I’d still love to run a short Amber campaign. Unfortunately, the game itself is now out of print. It’s designer, Erick Wujcik, passed away in 2008 and its publisher, Phage Press, no longer exists.
There is a spiritual successor to the game called Lords of Gossamer and Shadow. It shares the same rules and a default multiverse setting that sounds an awful lot like Amber.