Our daughter is 3 years and 3 months old and has the rules understood very quickly - I must, however, to say that we currently only with the colored cards (1 - 9 in 4 different colors) play and not the special cards (exposure, color change, +2, +4) also feature. But after a few laps the rule was clear and since then they play the game with mom and dad together very happy.
More than 2 or 3 rounds at a time are but because of their age still inside and of course she plays not foresight (which card I lie down, so that the next perhaps drauflegen anything) - but I just still too small. Nevertheless, they win very often - is not that suspicious? :-)
Great game, fair price, as always great and fast service from Amazon, again any time (is eh times be necessary a few cards are just already bent ...)