Tetra Master

Tetra Master is a card game created in the Squaresoft game Final Fantasy IX. It is not an essential part of the game but provids light relief to the storyline, and allows the player to interact with minor characters in a different way. Following Final Fantasy VIII's Triple Triad, Tetra Master is the second of the series to introduce a card mini-game.

Tetra Master is completely separate from the main storyline, and progression in the game does not affect achievement in the storyline, and vice versa. Tetra Master has become so popular it has spawned a PlayOnline version of the game allowing fans of the game to challenge others via the internet. The game would be very difficult to attempt without the aid of computer-enforced rules, but this is not to say it hasn't been attempted.

Game structure
Tetra Master is played between two players on a 4 by 4 square grid of blank spaces, where cards are placed as the game progresses. Cards are traditionally pictured with various characters, monsters or other items from the Final Fantasy IX game which are familiar to the player. More importantly, each card features four values written across the card, and may have arrows along the sides or in the corners of the card. The following image is an example of a traditional Tetra Master card:


 * [[Image:FFIX Tetra Master Hedgehog Pie.jpg]]

The basis of the game is cards challenge other cards, where values are assessed to decide the stronger card.

Card values
Every card has four values, or stats. In the example card above, the card has the stats 3-P-6-0. Each of these stats relate to the strength of the card. The second value (P) is always an alphabetical value, while the other three stats increase on a hexidecimal range, meaning they can range from 0-9, then through letters A-F.


 * The first value is for the power of the card. (3 above)
 * The second value is for the battle class of the card. (P above)
 * The third value is for the physical defense of the card. (6 above)
 * The fourth value is for the magical defense of the card. (0 above)

Each of the stats for power, physical defense and magical defense increase on a hexidecimal scale like below:
 * {| id="toc" |


 * weak &mdash;
 * 0 1 2 3 4 5 6 7 8 9 A B C D E F
 * &mdash; strong
 * }

Each of the stats represent a range of possible hit points (hp).
 * {| id="toc" |

!width="50"| Value !width="50"| Min !width="50"| Max
 * - align=center
 * 0 || 000 || 015
 * - align=center
 * 1 || 016 || 031
 * - align=center
 * 2 || 032 || 047
 * - align=center
 * 3 || 048 || 063
 * - align=center
 * 4 || 064 || 079
 * - align=center
 * 5 || 080 || 095
 * - align=center
 * 6 || 096 || 111
 * - align=center
 * 7 || 112 || 127
 * - align=center
 * 8 || 128 || 143
 * - align=center
 * 9 || 144 || 159
 * - align=center
 * A || 160 || 175
 * - align=center
 * B || 176 || 191
 * - align=center
 * C || 192 || 207
 * - align=center
 * D || 208 || 223
 * - align=center
 * E || 224 || 239
 * - align=center
 * F || 240 || 255
 * }

Whenever a card's value is assessed, a random value is chosen between the min and max numbers that correspond to the value. For example, if a card has a value of "A", the strength of that value may be between 160 and 175. The minimum value possible for stat are calculated by 16 multiplied by the stat. For example:
 * 16 x A (10) = 160.

Why values are assessed is explained later.



Power stat
The first value on the card is the power stat. This is the offensive value of the card. The example card (right) has a power stat of 3, which means its actual value is a number chosen between 48 - 63hp.

Battle class stat
The second value on the card is the battle class stat. This value is not based on the hexidecimal scale above, but instead is one of four classes. This stat is represented by the letters P, M, X, and A.
 * P is a Physical battle class
 * M is a Magical battle class
 * X is a Flexible battle class
 * A is an Advanced battle class

The battle class of the card determines how the values are assessed in card battles.

Physical defense stat
The third value on the card is the physical defense stat. This is the defensive value of the card when facing physical attacks. The example card has a 6, so this may be equal to anywhere between 96 - 111hp.

Magical defense stat
The fourth value on the card is the magical defense stat. This is the defensive value of the card when facing magical attacks. The example card has a 0, so this may be equal to anywhere between 0 - 15hp.

Stats
Card values are assessed when in a card battle.

Card arrows
As well as its stat values, each card may have a set of arrows in any of 8 directions. These points are usually referred to by using the traditional points on a compass (eg. north, northwest, west, etc.)


 * [[Image:FFIX Tetra Master Hedgehog Pie.jpg]]

The card above possesses two arrows at west and east on the card (the left and right sides respectively). These arrows come into play when cards are in an attack situation. An attack on a card may only be made when an arrow on the challenging card is facing the resting card on the grid. This is explained later.

There are a few scenarios where the arrows will not affect anything when played:
 * 1) The first card played will not affect other cards.
 * 2) When a card is played next to another card, but has no arrows pointing to the opposing card.
 * 3) A card is already on the board with an arrow pointing to a square and a new card is placed in that square, but the new card doesn't have an arrow pointing to the first card.

Should a card with an arrow facing west be placed next to a card possessing no antagonistic arrow facing back, the card is automatically captured.

Card battles only occur when a card with an arrow is placed facing adjacent to an card with an arrow facing back.


 * [[Image:Tetra Master card takeover.jpg]] – The blue card is taken by the red card


 * [[Image:Tetra Master card battle.jpg]] – The blue card challenges the red card to a card battle (see below)

Gameplay
In a basic game of Tetra Master, each player has 5 cards each, with no player knowing what each others hand holds. A coin-flip decision is made to which of the two players begin.

Grid blocks
Just before the game commences, it is chosen at random if any of the grid's squares will be blanked from game play using grid blocks. This may happen, and up to 8 blocks can be placed on the grid in any random fashion. Blocks are useless in play, and simply prevent a card from being placed in its grid square. Any arrow facing a grid block is useless.

A card is played
Once the game is set up, the starting player may play his first card anywhere unoccupied on the grid board. After the first card play, the opposition may play a card, and game continues with player turns alternating in this fashion.

Neutral card play
If a card is placed next to another card, they may interact. Should neither of the cards have arrows facing each other, there is no interaction. This is a neutral card play.

Card take-over
Should the challenging card have an arrow facing a resting card, while the resting card has no arrow facing in the opposing direction, the resting card is taken.


 * [[Image:Tetra Master card takeover.jpg]]

Card battles
Should the challenging card have an arrow facing a resting card, while the resting card has an arror facing in the opposing direction, a card battle takes place.


 * [[Image:Tetra Master card battle.jpg]]

It is in these situations the card stats are used.
 * The first two values are used for the challenging card.
 * The last two values are used for the resting card.

&mdash; Physical battle
If the challenging card has a battle class stat of P (physical), the power value of this card challenges the physical defense of the resting card. For an example of this, see below:


 * {| id="toc"

!align=center|Challenging card !align=center| Resting card
 * align=center|4P51
 * align=center|6M05
 * }
 * }

In the scenario above, the challenging card's power value (4) is assessed against the physical defense of the resting card (0). The challenging card would succeed, andthe resting card would be captured.

&mdash; Magical battle
If the challenging card has a battle class stat of M (magical), the power value of this card challenges the magical defense of the resting card. This works with the same principle of a physical battle.

&mdash; Flexible battle
If the challenging card has a battle class stat of X (flexible), the power value of this card challenges the weaker of the two defenses of the resting card.

&mdash; Advanced battle
If the challenging card has a battle class stat of A (advanced), any of the values of this card challenges the weakest of any of the values of the resting card.

Battle mathematics
When a card battle takes place, the successor is decided upon in three phases. Each of the phases are discussed below using the following example:


 * {| id="toc"

! !Card A ! !Card B
 * Example: || 5P33 || attacks || 2M10
 * Example: || 5P33 || attacks || 2M10


 * }


 * Phase 1:


 * The challenging card's power value is randomly chosen within the stat range.
 * say, 85 (stat 5 = between 80 and 95)


 * The defending card's defense value is randomly chosen within the stat range.
 * The challenging card's battle class is physical so physical defense is chosen.
 * say, 23 (stat 1 = between 16 and 31)


 * Phase 2:


 * Next, a random number is chosen between 0 and the power value chosen for the challenging card (85).
 * This is the actual attack score.
 * say, 71


 * A random number is chosen between 0 and the defense value chosen for the defending card (23).
 * This is the actual defense score.
 * say, 3


 * Phase 3:


 * The scores from phase 2 are subtracted from the stat values in phase 1.
 * Card A: 85 - 71 = 14
 * Card B: 23 - 3 = 20


 * The highest difference wins the card battle.

In the scenario above, even Card B with a low stats was able to defeat Card A.