Jump-In, Uno Wiki

Jump-In is an optional Uno rule. It states that if any player possesses a card of the exact same color and number/symbol as the card on top of the Discard Pile, he may immediately play said card at any time (as long as it is still matching and another card has not been placed on the pile).

Uno (card game) - Simple English Wikipedia, the free encyclopedia

Uno - Apache OpenOffice Wiki

Assault Synchron - Yugipedia - Yu-Gi-Oh! wiki

Tumblepop - Wikipedia

Uno (card game) - Wikipedia

Mohg, Lord of Blood

Ranked Mode, Uno Wiki

Uno Pizzeria & Grill - Wikipedia

Jump-In, Uno Wiki