Solitaire

Solitaire is a casual puzzle card game that combines traditional solitaire with numerical calculation. Unlike classic Klondike, this game centers around the numbers "0–21" — players must arrange, accumulate, or cancel out revealed cards according to ascending/descending order or specific arithmetic rules, with the goal of successfully organizing a complete sequence that fits the 0–21 range within a limited deck. Victory is achieved by legally processing all available cards according to the rules, or ensuring the final total falls within the valid 0–21 range.