UNO: Speed Pack Add-On of 16 cards introduces a new level of excitement to the classic UNO card game by speeding up gameplay and challenging players to match the increasing speed. Each "Speed Up" icon played raises the number of cards all players must play on their subsequent turns, starting from the next player. Initially, each player plays one card per turn, but with each "Speed Up" card played, this number increases incrementally, pushing players to play multiple matching cards or draw more cards. The Wild "Double Speed Up" card escalates the intensity by increasing the required card count by two levels and lets the player choose the next color. Action cards like Draw 2, Skip, and Reverse only activate when played as the last card of a player's turn. The speed resets once a player can't keep up, crashing the game's pace and returning it to normal until the next "Speed Up" card is played.
—description from the rulebook (adapted)