Pokemon Gb2 Slot Machine

All the slot machines have their odds randomly generated each play. As such, there is no single slot machine that is good for every player all the time. Generation 3: Generation 3 includes two sets of games: ruby/sapphire/emerald and fire red/leaf green. For Ruby/Sapphire/Emerald, the slots.

In Pokémon Red, Blue, and Yellow, there are playable slot machines in the Celadon Game Corner. The rules are apparently simple: The player needs to line up the same symbols on horizontal or diagonal lines (the set of available lines depends on the number of coins betted), and the player can stop the reels, one at a time, using the A button. In reality, the game may cause the reels to 'slip' after the A button press either to hinder or to help the player, and the rules for doing so are actually complicated, with many oddities that may or may not be glitches. (Together with the separate building for prize claims, this is comparable to how real life Japanese pachi-slots are played.)
Thanks to the disassembly, the actual behaviors of the slot machines in Generation I are completely understood, although at some places it may still be unclear whether they match the intended behaviors.

Overview

For each individual spin, the slot machine can be in one of three modes:Mode bad, which guarantees that the player cannot get any match in the available lines.Mode good, which allows the player to get matches of symbols other than sevens or bars.Mode super, which allows and actively helps the player to get matches of sevens and bars. Mode super is the only mode of the three that will persist between spins. It will only end when the player wins a reward of 100 coins (bars) or 300 coins (sevens), and in the latter case only with a probability of 50% (i.e. it still have a 50% chance to persist).In general, for each spin, the mode is set to mode good or mode super with probability 45/256 (~17.6%), with the probability of mode super further depending on which slot machine the player is playing on (see below). It is set to mode bad with probability 210/256 (~82.0%). There is also a chance of 1/256 (~0.4%) to enter a lucky streak which allows the player to play on mode good (but never mode super) for all the spins after this one, until the player wins 60 times.The function to set the mode, called before each spin

The lucky slot machine

Whenever the player enters the Game Corner, a random number between 0 ~ 31 is generated, and if it is 0, it has a 7/8 chance of becoming 1.More precisely, a random number between 0 ~ 255 is generated, it becomes 8 if it is less than 7, then it is divided by 8, discarding the remainder. See the function to generate the index of the lucky slot machine in the disassembly. Then, whenever the player plays on a slot machine, the number is compared with the index of that slot machine (0 ~ 35) plus one. If it matches, the chance of playing in mode super is set to 5/256 (~2.0%), and otherwise it is set to 2/256 (~0.8%).The function to set the chance of mode super
Effectively, this means that every time the player enters the game corner, there is usually a 'lucky slot machine' among the machines with index 0 ~ 30. The lucky slot machine is most likely (15/256, ~5.9%) to be the one with index 0 (the rightmost, bottommost one), and cannot be the ones with index 31 ~ 35 (the bottom five in the leftmost column). The other ones all have a probability of 1/32 (~3.1%) to be lucky, including the ones occupied by an NPC, or otherwise unplayable ('Out of order', 'Out to lunch', or 'Someone's keys'). Finally, there is a tiny chance (1/256, ~0.4%) that the lucky slot machine is the nonexistent slot machine -1.

Reel stopping

The mode of the slot machine comes into play when the player presses the A button to stop a reel, as the reel may 'slip' after the A press depending on its position. The exact logic for stopping the reel also depends on which reel the player is stopping. Internally, the first two reels are programmed to slip 4 times unless a condition is met earlier, while the third reel can either slip up to 4 times to help the player get a match, or slip any number of times to prevent a match.

First reel

In mode bad or mode good, the condition for the first reel to stop early is that the middle symbol is not a cherry. Since there are no two consecutive cherry symbols (in fact, there are no consecutive same symbols on any reel), that means the first reel will slip at most once.
In mode super, the condition for the first reel to stop early is that any of the three symbols showing is a symbol with an internal value less than that of the seven symbol. Since the seven symbol has the lowest internal value of all symbols, this condition is in fact never satisfied, and the first reel will always slip by 4 positions.The condition for the first reel to stop early

Second reel

In mode bad or mode good, the condition for the second reel to stop early is that there must be a 'potential match' on the first two reels, i.e. two of the same symbols that may form a line if the third reel stops in a good position. The player's bet is not considered; for example, a diagonal potential match counts even if the player only betted 1 or 2 coins.
In mode super, the condition for the second reel to stop early is that the potential match found is of either sevens or bars, or that there is no potential match and the bottom symbol on the second reel is seven or bar.The condition for the second reel to stop early

Third reel

In mode bad or mode good, the third reel will always slip to prevent a disallowed match, i.e. any match in mode bad, or a match of sevens or bars in mode good. There is no upper limit for the distance the reel has to advance this way; as an extreme example, hacking the game so that the reels contain all sevens will likely cause the game to softlock.The piece of code run after finding a match
In addition, in mode good or mode super, the reel will slip up to 4 times if no match is found. This is not counting the number of slips done to skip disallowed seven or bar matches in mode good, so the total number of slips may exceed 4.The piece of code run after not finding a match
Notice that, due to the design of the reels, there can never be more than one match at any time.

Oddities

On the spin where the player enters the lucky streak, the actual mode stays as it is on the previous spin, which can be either mode bad or mode good (the mode is initialized to mode bad at the beginning of a sessionAll the memory addresses from $CD3D (wStoppingWhichSlotMachineWheel) to $CD50 (wSlotMachineBet) are zeroed, which included the mode flag at $CD4C.). If the mode happens to be mode good and the player wins, it will still count towards the 60 wins to end the lucky streak. There is a line of code to immediately end the lucky streak if the player wins a reward of 300 coins, but this seems to be impossible, because the lucky streak is mutually exclusive with mode super, and mode good doesn't allow matches of sevens. The probability distribution of the lucky slot machine is weird in multiple aspects. The fact that one machine is more likely to be lucky and some others have no chance might be intended, but the fact that it can be the nonexistent slot machine -1 seems certainly an off-by-one error. The fact that the first reel's early stop condition in mode super is never satisfied is most likely a bug. Presumably, the intention is that the reel should stop if a seven symbol is showing, but the developers mistakenly wrote jr c instead of jr z. The second reel's early stop condition in mode super is weird in two aspects. The 'bottom symbol on the second reel' condition seems like an accidental use of leftover variable, although it may also be intended since there are two instructions specifically making it the bottom symbolThese two dec de instructions make de point to the bottom symbol of the second reel instead of the top symbol, and they seem to serve no other purpose.. The 'sevens or bars' check is only for the first potential match found, in the order of 'bottom-bottom, bottom-middle, middle-middle, top-middle, top-top' (i.e. from bottom to top), which means a potential match of bars may be rerolled if it appears above a potential match of another symbol.

External links

Analysis of how the slot machines in Pokémon Red, Blue, Yellow work by Crystal_:REDIRECT Template:YouTube

References

Location

In Pokémon Trading Card Game, this is the largest machine in the east room of the Mason Laboratory.

In Pokémon Card GB2: Here Comes Team GR!, this machine is in the northeast corner of the east room of the Mason Laboratory. It is also available anywhere by using the Minicom from the menu.

Mechanics

The player is able to save a currently used deck into this machine and retrieve a saved deck at any later point.

The player is able to choose which of the save slots is used to save the deck. There are 60 slots available in the first game and 50 slots available in the second game. If the player tries to save into a slot that already has a previously saved deck, they will be required to delete the previous deck if they want to use that slot. The number of currently saved decks and the maximum number of slots available are shown at the top of the Deck Save Machine screen. For instance, if the player has 3 saved decks in the first game, the number would be '3/60'.

In Pokémon Card GB2: Here Comes Team GR!, whenever the player creates a new deck, edits or dismantles an existing deck, the game asks if they want a copy of the configuration saved in the Deck Save Machine.

Deck status

The deck status is identical in the Auto Deck Machine and the Deck Save Machine.

Status	Pokémon Trading Card Game	Pokémon Card GB2: Here Comes Team GR!
The player has all the cards required and they are not in any other decks.	The symbol ○ is displayed near the deck.	No symbol appears.
	This deck may be completely built.
One or more required cards are in other decks.	The symbol ※ is displayed near the deck.
	The quantity of cards in other decks is unknown.	The quantity of cards in other decks is displayed near the ※ symbol.
	There is no way to see which cards exactly are in other decks.	The game displays a list of cards in other decks.
	The game offers to automatically dismantle any other decks with the needed cards.
	The deck may not be built if the needed cards are kept in other decks.	The deck may be built with replacement cards.
The player does not have one or more cards required for this deck.	The symbol × is shown near the deck, with the quantity of cards missing.
	The game displays a list of the required cards that the player does not have.
	This deck is unable to be built.	This deck may be built with replacement cards.
The deck has both issues above simultaneously. (the player doesn't have some cards, while other cards are in other decks)	The lack of cards takes precedence, so the cards in other decks are ignored.	Both issues are addressed simultaneously.
	The game displays the × symbol with the number of missing cards.	The game displays both the ※ symbol with the number cards in other decks and the × symbol with the number of missing cards.
	The game displays a list of missing cards.	The game separately displays a list of cards in other decks and a list of missing cards.
	This deck is unable to be built.	The game offers to dismantle any decks containing required cards. This deck may be built with replacement cards.

Options

English	Japanese	Notes
Save a deck	デッキをきろく	Saves a deck currently used by the player into the Deck Save Machine.
Build a deck	デッキをつくる	Builds a deck based on a saved deck configuration in the Deck Save Machine.
Delete a deck	デッキをけす	Deletes the currently selected deck in the Deck Save Machine
Cancel	やめる

In both games, press Start to check the cards in the deck. There is no visible command to do this in either game. (unlike the Auto Deck Machines, which have the 'Read the instructions' command to achieve this)

Starter decks

Pokemon Gb2 Slot Machines

In Pokémon Trading Card Game, the 3 starter decks are available in the Deck Save Machine at the beginning of the game. These are the same decks that are available to player character at the beginning of his journey. They are able to be deleted from this machine, like any other saved deck.

They are not exactly the same as the decks found in the first Auto Deck Machine, which share the same name in English, but have different names in Japanese.

Pokemon Gb2 Slot Machine Simulator

In the European versions, there is no way for the names of these decks to keep up with language changes in the options. The names of these decks remain the same as when the game started, except the word 'Deck', which changes between languages. For instance, if the player chooses to start a new game in Spanish, then the first deck is named 'Mazo Charmander y Amigos'. If the player later changes the language to English, this deck will be shown as 'Charmander y Amigos Deck'.

In Pokémon Card GB2: Here Comes Team GR!, the Deck Save Machine does not have any saved deck at the start of the game. The Starter Deck (the deck the player started with) is available at the Auto Deck Machine instead.

In other languages

Language		Title
Japanese		デッキきろくマシン
Machine a Sauvegarder les Decks
Deck-Sicherungsmaschine
Macchina Salva Mazzo
Máquina de Guardar Mazos

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