Our rules include...
For example, suppose I play a Yellow Draw Two and then Aon plays a Green Draw Two and Hector plays a Blue Draw Two. If I do not have another Draw Two or Wild Draw Four card, I have to draw 6 cards! If multiple Wild Draw Four cards are played when this happens, it can add up fast!
For example, suppose I play a Green 5 and the Hector plays a Wild Card and changes the color to Red. Aon could then play any Red Card or a 5 of any color.
For example, suppose Hector plays a Blue 6 and then play passes to me. If I cannot play and have to draw, I can draw up to 6 cards. If I draw a card that I can play before I reach 6, then I stop drawing cards and play that one. I'm left with the cards that I drew that I couldn't play.
For example, suppose Aon plays a Yellow 7. Hector can then play a Blue 3 and a Blue 4 or a Green 6 and a Green 1 or a Red 5 and a Red 2.
For example, suppose Hector's last card is a Red Draw Two and he plays it. Aon then plays a Wild Draw Four and changes the color to Blue but I play a Green Draw Two. Hector then must draw 8 cards and is back in the game! He should have thought ahead!
For example, Hector plays a Yellow 5 calls Uno! Aon then plays a Yellow 9 and then Hector plays a Yellow 2 and goes out. Poor Aon has lost!