It would be heresy
for me to tell you the rules
. The only rule I can tell you is this one.
It is best to learn to play under a Mao master, but if there aren't any around, you have to make due however you can. There are many, many versions of Mao out there, but this is the one that seems most familiar to me, as lots of people played it in my high school. So, here is a sample game which should allow you to divine the rules if you study hard and pay attention.
There are four players, Andy, Daryl, Justin, and Kyle. Andy and Daryl know the game quite well, Kyle has played a couple of times, and Justin has never played. Andy and Kyle smile at each other. It's the smile you smile when you know a secret that nobody else does, and you know you're going to get some quality entertainment out of it. A look of intense concentration has come over Kyle... this time he's going to pick up the last few rules that he hasn't figured out. Justin looks confident and in control, even though everybody knows he's completely bewildered. That's just the way Justin is.
Andy is the dealer. Daryl is sitting to his left, Kyle is across from him, and Justin is to his right. Andy shuffles two decks that look totally different into the same pile, and begins to deal. He hands out cards face down, starting with Daryl, until everyone has five cards. He places the rest of the pile in the center, face down.
Justin picks up his cards. No one else moves. They are all looking at him. He quickly puts his cards down as Andy reaches to the pile, picks up a card, slides it face down to Justin, and says "Touching cards too soon."
Justin laughs, "You dirty bitch!"
Andy calmly slides yet another card to Justin. "Swearing." Before Justin can do anything else dumb, Andy picks up his cards and says "The game is Mao. Play will proceed to my left." He places the top card on the pile face up on the table, forming a discard pile. The card is the 4 of Spades. Andy then says "4 of Spades."
Daryl right away throws a 9 of Spades onto the top of the discard pile and says "9 of Spades".
Kyle puts down a 9 of Hearts.
Justin's got the idea. He lays a 7 of Hearts and says "7 of Hearts." He looks around expecting looks of amazement due to his fast learning.
Andy studies his cards for a moment, then reaches to draw a card. He pauses, looks at Justin, and then takes two cards off the top of the pile and slides them to him, saying, "Unnecessary talking; failure to say 'Have a nice day'." Justin groans, and Andy again reaches for the pile, but this time takes a card for himself and says, "Penalty card."
Daryl plays a Jack of Hearts, and immediately Kyle shouts "Spades!" as Andy says "Diamonds!"
Andy then says "Point of Order" and everyone but Justin puts down their cards. "Touching cards during a P of O," Kyle says as he slides Justin another card. Justin takes the card and puts it into his ever-growing hand.
"Touching cards during a P of O!" urges Daryl as he passes another card Justin's way. Justin wisely puts down his cards and doesn't touch the newest one. He now is the proud owner of 10 cards.
"Anyway," says Andy, "who called first? Me or Kyle?"
"Kyle got it," says Daryl. "Spades. End Point of Order."
Everyone picks up their cards. Justin is the last to do so, and before play resumes he says, "Wait, so can anybody end a Point of Order?"
Everyone puts their cards back down, and Justin is quick to follow suit. Daryl passes a card to him. "Asking about the rules."
Justin doesn't touch his card yet. "So, are we in a Point of Order now?"
Andy passes him another card. "Saying P of O while in a P of O."
Andy says, "Remember, we're on Spades. End Point of Order."
Kyle lays a 7 of Spades and says "Have a nice day!"
"Failure to say '7 of Spades'," Daryl says as he passes a card to Kyle.
"Penalty Card," Justin says as he takes another card. He's starting to learn now.
"8 of Spades" says Andy as he plays an 8 of Spades.
At first, Daryl doesn't do anything, then he takes a card and passes it to Justin. "Failure to play within 5 seconds."
Kyle plays a 3 of Spades and says "3 of Spades."
Daryl plays a 3 of Clubs.
Andy glares at his cards for a moment, then picks up a card from the face down pile and puts it with his hand.
Justin plays a King of Clubs.
Kyle plays an Ace of Clubs and says "Last Card!"
Daryl sulks, glaring at Kyle.
Andy plays a 2 of Clubs.
Justin lays a 7 of Clubs and astutely says "Have a nice day!"
Smiling, Kyle plays his last card, a 7 of of Diamonds, and says "Have a very nice day!" He is now completely out of cards.
Andy grins and slides a card to Kyle. "Failure to win," he says.
"Oh, man, I forgot!" exclaims Kyle, and Justin quickly passes him a card. "Talking."
The game continues. Andy lays another 7 of Hearts and says "Have a very, very nice day!"
Daryl takes a card. "Penalty Card."
Kyle draws a card out of the pile.
Justin sets down a 6 of Spades.
Andy passes Justin a card. "Failure to call the card." Justin accepts his penalty, unhappily eyeing his 12 cards. Andy then lays an Ace of Spades on the discard pile and says "Ace of Spades."
Kyle pauses for a second, then jolts upright and quickly plays a 2 of Spades and says "2 of Spades."
Justin pauses, hoping there's not some other rule that's going to hit him this time. He plays a 2 of Diamonds.
Andy puts down a 2 of Hearts and says "Last Card."
Daryl lays an 8 of Hearts and looks apprehensively back to Andy.
Andy smirks and puts down his final card, and 8 of Diamonds and says "Mao."
Everyone returns their cards to the pile, and Daryl begins a new game, dealing 5 cards to each player. "The game is Mao; play will be to my right." He glances at Andy. "A new rule is in effect." Unbeknownst to anyone else, Andy's new rule is that any Diamond skips two players. This overrides any rules already governing the Ace of Diamonds. Daryl turns over the top card on the face down pile. It is an Ace of Hearts.
Andy plays an Ace of Diamonds.
Kyle plays a 2 of Diamonds.
Andy slides Kyle a card and says "Playing out of turn," and then turns to Daryl, gives him a card, and says "Failure to play."
Daryl, with a look of consternation, accepts the card. Kyle, however, passes it back and shouts "Bad call!" Andy slides the card back at him and says "New rule..."
...and the game continues...