Here were the parameters in my head when I started trying to hash out the design for Solo Dice Quest:

• Like in To Court The King, you start with 3 dice and gain both dice-adding and dice-modifying abilities.
• Both dice-adding and dice-modifying abilities should be necessary.
• Unlike in To Court the King, in the course of a single “round” the number of rolls you get is fixed. This should make dice-modifying abilities relatively more useful. One problem with TCtK is that no dice-adding ability is ever worse than “reroll all your dice.”
• The final goal will be to try to roll a large n-of-a-kind. The number required will be decided during the game.
• Half the “rounds” will be “quests” in which you try to match one of a small number of patterns. When you match a pattern, you take its card and gain the associated ability. (This is like TCtK except that not all of the patterns are available to you on any given turn.) The power and difficulty of the quests increases as the game progresses. Getting abilities from earlier in the game should make the difficulty of later quests manageable.
• The other half of the rounds will be “trials” in which you attempt to fulfill a certain condition. The catch is that this condition becomes more difficult as you get more dice, such as “all of your dice are 4 or greater”. Thus, choosing only dice-adding powers and eschewing dice-modifying abilities means you will fail at trials. Failing at trials has no immediate consequence, but it increases the difficulty of the endgame.
• The win rate should be 30-50%, increasable by some kind of “easy mode”. Winning should feel like an accomplishment even for a seasoned player.
• Winning a “round” as the game progresses should be expected but not guaranteed. Losing 0 or 1 rounds total should make the endgame very manageable–as long as you didn’t take only dice-modifying abilities and now you don’t have enough dice to win! Losing 2 to 4 rounds should make it dicey. Losing more rounds should make winning the endgame a long shot.

Near future: The outline for a multiplayer game based on the same framework, and the problems it is going to have; also, refinements of these ideas along with specifics; where it went when I started taking Sharpie to cardbord.