These are adding games, in which the values of the cards are added together as they played in a single pile, the object being to avoid taking the total above the target score (98, 99, 100 respectively). These games presumably have a common origin, since the details, including even the effects of the special cards are similar, and to judge from the correspondence I have received, they probably originated in North America in the mid 20th century, even though it is not documented in the card games books of that period. I have received two reports from families who played 98 in the 1970's and and one who played 99 in the 1950's.
Kantaphon Tongmee tells me that a similar adding game 99 (เก้าสิบเก้า) is played in Thailand.
Note that there are also other, entirely different card games called 99 and 100. There is Ninety-nine, the three-player trick taking game invented by David Parlett, and the Chinese partnership trick-taking game of Hundred.
There are many slightly different versions of 98, and the original Arizona game has some complications which were dropped as it spread more widely. For clarity, we first describe one of the simpler, later versions. Rules for the more complex original game are given below.
As described by Chris Jepson, 98 is a fairly simple drinking game for 2 or more players, using a standard 52 card deck.
Deal out four cards to each player and place the remainder face down to form the stock. The player to the dealer's left begins and play continues in clockwise order. Players play their cards on the table to form a face-up pile alongside the stock.
At your turn you play one of your four cards to the face up pile, call out the new value of the pile, and then draw the top card from the face down stock to replace the card you played.
At the start of the game there are no cards in the pile and its value is zero. Played cards affect the value of the pile as follows:
The aim is to avoid taking the value above 98. The first person who makes the value of the pile more than 98 loses, and has to take a drink.
Example. The first player plays an 8 and says 8; the next player plays a 6 and says 14; the next player plays a king and says 98; the next player plays a jack and says 98; the next player plays a ten and says 88; the next player plays a 7 and says 95; the next player's four cards are 4, 5, 6, 9 - this player must lose.
John Peterson reports a variant from UMass Amherst in which there are additional special cards.
In 1993 Jay Feaster and his friends Sully and Dave at Arizona State University created a variant of 98 with some extra complications that are not found in other versions of the game. The players took this game back to their home towns and taught it to their high school friends during vacations, and from there it spread to other colleges, though in some cases with simplified and streamlined rules. The original Arizona version is as follows.
A standard 52-card pack with two jokers is used. Four cards are dealt to each player, and the remainder are stacked face down to form the stock. The player to the dealer's left begins and play continues clockwise. Players play their cards to the center of the table to form a face-up pile alongside the stock.
Note. Originally the play pile began empty, but later the custom was introduced that the dealer would turn up the top card of the stock to begin the play pile. If this first card was a special card its effects would apply immediately, which would be unlucky for the first player if it was a king or joker.
An ordinary turn consists of playing one of your four cards on top of the face up pile, adding its value to the current total, calling out the new value of the pile, and then drawing the top card from the face down stock to replace the card you played.
The pile value must not go above 98. If a player is unable to play without taking the total over 98, that player is eliminated from the game. The play does not end, but the turn passes to the next player after the one who was eliminated. Play continues until either all players but one are eliminated or the stock runs out. The last person who managed to play a card is the winner.
2, 3, 5, 6, 7, 8 and 10 are ordinary cards. Playing one of these simply increases the value of the pile by the face value of the card. All other cards have special effects when played, as follows.
If a player has two, three or four cards of the same rank, they can be played together and the pile value is increased by the total value of the cards played. For example, playing two 8's together increases the pile value by 16. When multiple aces are played, they must all be given the same value - for example three aces increase the pile value by 3 or 33 (not 13 or 23). After a multiple play the player draws the same number of cards that were played, so as to have four cards in hand again.
A joker sets the value of the pile to 98 and there are three possibilities for next player.
If your first play on the joker is a 4, 9, J, Q or K the pile value returns to 98 and you must play again. If your second play is also a 4, 9, J, Q or K, that completes your turn and the next player will only have to make one play as usual. If your second play was a Jack, the new pile value will be 88, otherwise it will be 98. If one of your plays was a 9, the turn goes back to the player of the joker. If both your plays were nines the direction is reversed twice and the turn goes on to the next player. If your second play is a joker, then the next player in turn must again play twice on 98, so by playing a 9 followed by a joker you can turn the tables on the person who played the first joker, making then play twice on 98.
It would theoretically be possible to play both jokers together, using the multiple play rule, though in practice this never happened. If both jokers are played, the next player is required to play four times on 98. In other words the next player's four cards must all be special cards that do not increase the pile value (4, 9, J, Q, K). If unable to do this, the player is eliminated and the obligation to play four times on 98 passes to the following player. Thus a play of two jokers is quite likely to eliminate all the other players and thus win the game.
It is traditional for the dealer to take a good card from the deck and place it face up at the bottom of the stock as a reward for the last player who is able to replenish his hand from the stock. When the stock is exhausted, play continues without hand replenishment. If you have no card left to play on your turn you are eliminated from the game. The play ends when all players but one are eliminated: this can happen either before or after the stock is used up. The winner is the last player who played a card to the pile. The winner receives a "party favor"and has to shuffle the cards and deal the next round.
Note: This game should not be confused with David Parlett's Ninety-nine, which is a trick-taking game in which the cards discarded define the bid.
Each player begins the game with 5 pennies (or chips). Deal out 3 cards to each player from a standard 52 card deck (if more than 4 people are playing use 2 decks and give each player just 3 pennies). The undealt cards are placed on the table to form a face-down stock.
The player to the left of the dealer starts and the turn initially passes clockwise. On each turn you play one of your three cards face-up to the centre of the table, call out the total value of the face-up pile (as per the table below), then draw the top card from the stock. When the face-up pile is empty the count is zero. For each card played add the pip value of the card played to the total value of the pile. Jacks and queens count as 10. The following cards cause special effects:
If you cannot play without taking the value of the pile over 99, you lay down your hand. The play ends, and you toss one penny into the center; players who have no pennies left drop out of the game. After each hand, the deal passes to next player to the left of the previous dealer who is still in. Hands continue till only one player has any pennies left, and that player is the winner.
When someone plays a nine or a four they repeat the value of the pile, calling out "pass to you #" or "back on you #" respectively. For example here is part of a four-player game; play is currently running clockwise. Player 1 plays a King and says "99". Player 2 plays a nine and says (looking at player 3) "pass to you 99". Player 3 plays a four and says (looking at player 2, since play order will now run counterclockwise until another four is played) "back on you 99". Player 2 plays a ten and says "89". Player 1 plays a eight and says "97". Player 4 plays a four, looks at player 1 and says "back on you 97" (now we're back to clockwise), and so on.
When there are only two players, there is no longer any difference between clockwise and counterclockwise play. the player to your left is also the player to your right. Therefore, playing a four has no effect on the turn order when there are two players - the pile value remains the same and it is the other player's turn, just as though you had played a nine.
If the stock pile runs out, the top card of the discard pile is set aside to begin a new discard pile (the count is unchanged) and the rest of the pile is shuffled to form a new stock, so that the game can continue.
This game should be played very rapidly. It is easy to forget to draw a replacement after you play a card. If that happens it cannot be corrected afterwards - you must get by with one fewer card for the rest of the hand.
The number of coins players have at the start of the game can be varied, as can the number of cards in each player's hand. For example Alan Orcutt reports a variation in which everyone starts with 4 nickels and five cards are dealt to each player. In Don Boyer's version players are dealt seven cards each, and effectively only one coin, since a player who goes over 99 is immediately eliminated from the game. However many cards are dealt, a turn consists of playing a card and then drawing a card, so that the number of cards in each player's hand remains the same for each turn.
Frankie Kolb describes a version in which that each player begins with a dollar bill and folds over one corner each time they go over 99. A player who has folded all four corners is out of the game and the last survivor gets all the dollars.
Some play that after a player goes over 99 and loses a coin, the pile is taken away and the other players continue to play with the cards they have in their hands, starting a new pile from zero. If the stock runs out, the played cards are shuffled to form a new stock pile, but the running total of the pile is preserved.
As one might expect, there are variations in the special cards and their meaning. Some interchange the Nine and the King, so that a King is worth zero (the player says "pass me by") and a Nine sets the total to 99. Some interchange Four and Nine so that a Nine reverses direction and a Four leaves the count unchanged. Some play that a Ten always reduces the count by 10 - it cannot be used to add 10. Some play that an Ace may be counted as either 1 or 11.
Some people consider that the four, which normally reverses the direction of play, should have some effect on the turn order even when there are only two players. If this is your opinion, you can agree to play the alternative rule that when there are only two players, playing a four entitles the same player to play again.
Daniel Stack describes a version played in the 1950's in which each player began with three pennies. A player who lost all their pennies was allowed to play 'on their honor' and was eliminated if they lost again. The last survivor was the winner and collected all the pennies. There was no card that set the total to 99. The only special cards were:
Brad Wilson describes a version with the following differences:
Some play that making the total exactly 69 has some sort of effect. It might be a bonus - for example scoring an extra point, or getting a penny from the pool, or everyone else having to take a drink if you play this as a drinking game, or some other result such as resetting the total to zero.
In the version described by Ishihara, after the deal a card is turned up to start the play. If it is a special card it is returned to the middle of the deck and the next card is turned up. When an ordinary card is turned, this card gives the initial count from which play begins. In this version there are no coins and players who go over 99 are immediately eliminated. However, it is forbidden to set the total to 99 by playing a King during your first five turns. Ishihara's group also have a variant where certain hands immediately end the game - a player who has three Kings immediately wins, and a hand of three Sixes causes the game to end immediately with all players losing.
This section is based on a description posted to rec.games.playing-cards by Nicholas Cheung.
Note: this game is not to be confused with the Chinese game of Hundred (Da Bai Fen) in which the aim is to win kings, tens and fives in tricks.
One normal deck of 52 cards is used for 3 to 6 players. If there are 7 or more players 2 decks are used. Each player begins with three chips and the object of the game is to be the last player to have any chips left.
Three cards are dealt to each player, one at a time, and the remaining cards are placed face-down on the table to form a stock. The cards put down by the players will form a face-up pile beside the stock. At the start of the game there are no face-up cards and the value of the (empty) pile is zero. The player to the left of dealer begins and the initial direction of play is clockwise. At your turn you put down one card face-up on the pile, say the new value of the pile, and draw the top card of the stock to replace the card you played.
Most of the pip card are worth their face value, which is added to the value of the pile. Queens other than hearts are worth ten. So for example the first player might play a nine, saying "9" and the next player might put a six on it saying "15", and so on.
Certain cards have special effects as follows:
| Black Aces | The player can set the pile value to any number from 0 to 100. |
| Two of Spades | Doubles the previous value (for example if the previous player made the pile 36, adding the  2 will make the new value 72) |
| Fours | The pile value is unchanged but the direction of play is reversed. |
| Red Fives | Deduct 5 from the previous pile value (i.e. red fives are worth -5). |
| Tens | Set the pile value to 100. |
| Jacks | Deduct 10 from the previous pile value (i.e. jacks are worth -10). |
| Queen of Hearts | Set the pile value to zero. |
| Kings | The pile value is unchanged (i.e. kings are worth zero). |
The aim of the game is not to be the player who takes the value of the pile over 100. If you are unable to play a card keeps the value to 100 or less, you lose one chip. A player who has lost all three chips is out of the game. The last player who has any chips left is the winner.
Example: if the player before you makes the pile value 100, the only cards you can play are black aces, fours, red fives, tens, jacks, the 
Q and the kings.
If the stock runs out, all the played cards except for the last one are reshuffled to make a new stock and the game continues from the same count.
Here is an archive copy Brad Wilson's former Ninety-nine page.
This page is based on contributions from several players, including Don Boyer, Nicholas Cheung, Jay Feaster, Anita Hollister, Ishihara, Chris Jepson, jimspumpkins, Frankie Kolb, Alan Orcutt, John Peterson, Daniel Stack, Stephanie and Brad Wilson.