Tectonica Rules

Object of the game

The object of the game is to either push your tectonic plate far enough to win, or push the opponents plate back enough for them to lose.

How to setup:

To set up the board all you have to do is place the tectonic plates four spaces in from the edge of the board.

Numbers of players:

This is a two player game.

What a common turn looks like

In most turns, you will:

1. Roll die

2. Hold which die you want to keep and re-roll the rest

3. Repeat step 2 once more

4. Move tectonic plates

5. Roll for earthquake (if you want and do not have the volcano chip)

In-depth description of each step:

Step one: Roll die

In this part of your turn, you roll all the die, and pick which ones you want to keep.

Step two: Hold die

In this part, re-roll the die that you do not want to keep.

Step three: Repeat step two

Just repeat step two.

Step four: Resolve dice

Once you have rolled the die, you must resolve what they do.

How to resolve dice:

If you rolled more than one of a 1, 2, or 3, move your plate forward on space for each die in the streak. This is the start of making a convergent plate boundary.

If you get a ascending streak, you move the opponents plate back one space for each die. You must have at least three die in the streak though. This is how a mid-ocean ridge is formed.

For each six you roll you get to move your plate one space forward. This is another way to create subduction.

If you roll a five or four, you can choose to try to make a volcano. To make a volcano, you must choose any number from one to six, and roll the four or five you are using in the creation of the volcano. These die also cannot be used in other streaks. If you roll the chosen number, you successfully make a convergent plate boundary, which also leads to a volcano. If you make a volcano, you get the “volcano” chip, which allows you to have one extra re-roll each turn. The most recent person to make a volcano should always have the volcano chip. You can try to make a volcano more than once in a turn.

Other rules:

1. If both of the plates are within four spaces of the middle, they form a convergent plate boundary. This makes it so you cannot move your player forward, only move the other player’s plate back. This is because of convection currents pushing the plates apart.

2. If you move the other player’s plate back past the last line, they lose. If a player’s plate crosses or lands on the middle line they win, because they have made a convergent plate boundary.

3. If you don’t have the volcano card, you can also try to cause an earthquake. To cause an earthquake, you must choose any number from one to twelve except seven, and then roll two die. If the sum of the two die is the same as the number you choose, you create a reverse fault, so the enemy player cannot move their plate for two turns. If you roll and it is within one of the number you choose, you creat a strike-slip fault, and the enemy player cannot move their plate for one turn. If you roll a two, you create a normal fault, and this causes your plate to move back two spaces, and on your opponent’s next turn, if they have a roll that is supposed to move their plate forward, they actually move it back that number of spaces.

4. If the first two turns have rolls that win the game, re roll them immediately.

Probability:

The chance of rolling a ascending streak of six on your first roll is ¹⁄₄₆₆₅₆, but for every time you re-roll your chances increase. This is because if you roll six die, and there is a one in 6 chance of rolling the right number on each, the equation is ⅙ x ⅙ x ⅙ x ⅙ x ⅙ x ⅙ = 1/46656.

The chance of getting three threes on your first roll is 1/216, but re-rolling gives a much higher chance of getting it. This is because of if you roll a three on one of the die the chance of rolling another two three’s is less likely. The equation of rolling this is 1/6 x 1/6 x 1/6 = 1/216.