EXTINCTION:
THE GAME

Listed below are the full rules that come with the game Extinction. There is also a short version. You should read the short version first and then come back to this page to get more details. We have made a few changes which are included in the short rules. In case of discrepancies your lab instructor is the referee.

Table of Contents


Introduction

Extinction is a board game for two, three, or four players. It is designed both to entertain and to illustrate certain principles of ecology. The game deals with some of the key processes by which species survive and evolve, or become extinct. It also illustrates the complex and sometimes devastating chain reactions which may be started by changes in the environment, particularly those caused by man.

The game consists of several species of make believe animals competing ecologically on the imaginary island of Darwinia (the game board). Each player plays one species. Winning Extinction consists of either (1) the winner’s species being the sole survivor on Darwinia, or (2) the winner’s species being the most abundant after some agreed upon time has passed (see Winning a Game).

The island of Darwinia is divided into six distinct habitat types. The player’s species is represented by a series of colored population cubes. The number of cubes a player has on the board depends on how abundant his population is at the moment. (You may see a larger view of the board with some description here.)

The player tries to determine the best competitive strategy for his species at each moment in time as the game progresses. The task is difficult because each player has only a limited knowledge of the continually changing genotypes of his competitors and because his species is subjected to changing environmental stresses. The moves made by the players are determined by spinning a chance wheel which is divided into different ecological events.

The player’s strategy is complicated further by the actions of man. In Extinction man builds cities and jetports, causing air pollution. Sometimes he sets fire to woodlands or meadows, and sometimes he pollutes lakes and marshes. He may also clear brushland for grazing, fill marshes with garbage, or cut down woodlands for framing. Such human activities can upset the competitive balance between species in the game, and can even by the direct cause of the extinction of some species.

Rules of the Game

Game Elements

The elements of the game of Extinction consists of (1) a Game Board, (2) a Spinner, (3) six sets of Gene Cards, (4) one set of Environmental Change Cards, (5) a set of 10 Barrier Pieces, and (6) four sets of 20 Population Cubes (dice).

The board shows a habitat map of the island of Darwinia. Each habitat type has a color and a symbol code as explained on the board. The habitats are divided into units called habitat hexagons.

How to Begin

Each player has a set of 20 population cubes on one color. A player occupies a particular habitat hexagon on Darwinia by putting one of his cubes on it. No more than one cube, whether of the same or different species, may occupy a given habitat hexagon at one time. The number of dots (1 to 6) uppermost on the cube tells how many individual animals presently occupy the habitat hexagon. Thus, the largest attainable population size is 20 x 6=120. All further discussion of numbers of individuals refers to dots, not cubes.

Determine the order of play by throwing any pair of population cubes. The lowest scorer goes first; after that, the colonization and all continuing play move clockwise.

NOTE: The rules that follow have been changed for our lab. See the short rules for the way we will start play.

Each player puts 30 individuals of his species on the island as a “founder” population. These 30 individuals are represented by the total number of dots showing on all of the player’s cubes on the board. These individuals may be put into any unoccupied habitat hexagon on the island. They may be concentrated in a few habitat hexagons or spread thinly across the whole island as long as the total number of individuals (dots on cubes) adds to 30.

After all of the players have colonized the island, the play passes once more to each player before the game actually begins. The second time around, each player may, if he likes, relocate his 30 individuals relative to those of his competitors.

Once this second round is over, all players draw their first set of gene cards, one card from each of the six gene card decks. (Environmental Change cards are not gene cards, and are not drawn with the others.) Then play begins. At his turn, each player spins the spinner to determine what ecological actions he may take. The spinner is marked off in pairs of ecological actions:

Moves of the Game

The player must reproduce, change the environment. Or place a barrier whenever the spinner lands on these events. All of the other actions are optional. For example, the player may choose not to migrate or change genes. Note that actions occur in pairs on the spinner. If both actions are taken by the player, he must perform the first listed action first.

Required Moves

Reproduce. Not all individuals of a player’s population are reproductive. The species reproduces only in optimal habitats as specified on the Habitat & Mobility card. To find out how many newborn animals to add to a population, count the number of individuals of the population in the optimal habitats. Multiply this by the number on the Reproduction card. It may be necessary to round off to the nearest whole number; for example, if you get 4.5, round this off to 5 animals. Add the resulting number of new animals to the population.

The newborn animals may be added to the population in two ways. The player can turn some to the cubes already in optimal habitats up to bigger numbers. Or, now animals can be added to hexagons adjacent to the reproductive animals in optimal habitats. If the adjacent hexagon is empty, add a new cube. If it already contains your cube, turn it to a larger number.

The player must add as many of the newborn animals to his population as he can. Sometimes adding all of them is impossible, particularly when a player’s population is boxed in by other species. In such cases, the player must turn all his cubes adjacent to or in optical habitats to six, thereby adding as many new animals as he can.

Environmental Change. The player draws from the top of the deck an Environmental Change card which will name the kind of change that has just occurred. These changes can cause mortality in the populations of one or more species. Species can be tolerant of some of these changes and not others, depending upon their Environmental Tolerance card. Some changes are natural; others result from the actions of man.

After all of the effects of the environmental changes have been produced, the Environmental Change card is returned to the bottom of the pile.

Not all changes are for the worse. A “mild season” gives a player the chance to take any set of paired moves on the spinner he chooses, except another environmental change. Cards with these changes state: “Mild Season – Choose any Paired Moves on Spinner except Environmental Change.” After the player takes the moves of his choice, he returns to the second of the original moves on the spinner.

Four factors (Famine, Pestilence, Drought and Cold Wave) are natural environmental changes and act only on the species of the player drawing the card.

Famine and Pestilence are changes which eliminate only individuals in those habitat hexagons that are densely populated by the player’s species: hexagons containing five or six individuals. The player who draws either of these changes must remove all of his cubes which show five or six dots. Thus, if a player’s hexagons are everywhere populated with cubes tuned to five or six, his species will go extinct if famine or pestilence strikes.

Cold Wave and Drought are changes which cause no mortality in tolerant species, but causes 10, 30, or 50 percent mortality in nontolerant species, no matter how big the population is. Determine the number to remove by multiplying the total population size (the total number of dots showing on all of a population’s cubes) by the percent figure on the card and round off to the nearest individual. Players can decide which animals to remove from the population.

The following changes apply to all players, regardless of which player draws the card. These changes eliminate all of the individuals of nontolerant species found in the stricken habitat. Survival is determined by each player’s Environmental Tolerance card.

 

Fires, natural or man-made, may burn any of the “land” habitats: woodlands, meadows, or brushlands. Water pollution may strike any the “water” habitats: marshes, lakes, or swamps.

Air pollution strikes cites and jetports, two of the five kinds of barriers in Extinction. When this happens, all individuals of any nontolerant species are eliminated from hexagons adjacent to city and jetport barriers.

In Extinction no species is able to defend itself against certain man-caused changes: clearing woodlands or brushlands, draining swamps to make farmland, using marshes as garbage dumps, filling lakes, and overgrazing meadows with domestic livestock. Whenever these changes occur, all species are eliminated from the stricken habitat. The habitat may be repopulated later.

Place Barrier. The player must place one barrier of his choice in any hexagon not presently occupied by (a) another barrier or (b) the last (sole surviving) population cube of a species. Except for (b), any individuals in the hexagon are removed and the cube returned to its owner. Habitats already occupied by barriers cannot be occupied by any species.

Optional Moves

Migrate. A part of a player’s population can be moved from one place to another on the island of Darwinia. The ability of a species to migrate depends on its Habitat & Mobility card. The player may move his species in any combination of ways such that the number of individuals moved, times the number of hexagons traversed, is no larger than the mobility number of his Habitat & Mobility card. A player need not use his maximum mobility; in fact, he can choose not to migrate at all in any given turn.

For example, if a player’s species has a mobility of 20, he may move one individual a distance of 20 habitat hexagons, or two individuals 10 hexagons, or three individuals six hexagons and one individual two hexagons, and so on. (If you wish to split the population o a particular hexagon, remember to subtract the moved animals form the number of the cube in the original hexagon.)

A player may not migrate through habitats occupied by other species or by barriers he cannot cross (see the Barrier Crossing card).

Compete/Prey. A player may compete and prey in the same turn. However, he can only use each cube once per turn and he can only remove rivals adjacent to hexagons he occupies.

COMPETE. A species may compete only against those adjacent rivals whose particular cube shows fewer individuals. In occupying the captured hexagon, the player may split his individuals, but he must replace the rival with more individuals than the rival had in the hexagon (thus, if you are taking three individuals with six, you must move at least four individuals into the new hexagon).

PREY. To prey, the player announces his predator type (strong, swift, and so on). Rivals occupying adjacent hexagons whose Prey Defense cards defend them against this type of predator must show only that word on their Defense card as proof. Those rival species undefended against the player’s species become prey. The predator may then occupy the prey’s hexagon with part or all of his individuals form an adjacent hexagon. A player may want to use just one individual to occupy a rival’s hexagon populated by as many as six.

Competition and predation may take place across any barrier which the player’s species can cross (see the Barrier Crossing card), as if the habitat hexagons across the barrier were adjacent.

Return cubes displaced by competition and predation to the appropriate players.

Change Genes. A player may change form one to four gene cards in a turn. The player may not change any gene card more than once in a turn. He returns his unwanted cards to the bottom of the appropriate deck before drawing his new card from the top of the deck. Thus, if a player decides to change a genotype, he takes his chances on which card he gets.

Winning a Game

Decide at some time in the game whether to play until only one species remains on Darwinia, or to play to the end of some specified time. Games played to one surviving species often take longer than three hours. Set a time limit if you want a short game.

In a game with a time limit, the final population score of each player is determined by counting the individuals on all his cubes showing one, two, three, or four dots. The player with the highest score wins, the next highest player is second, and so on.

This method of scoring means that sheer abundance will not necessarily win the game. In nature, overcrowded populations have poorer long-term survival chance than less crowded ones. In the game, hexagons containing five or six individuals are inevitably struck by a famine or pestilence at some time, unless their densities are reduced by other factors. Hence, they contribute less to the long-term survival of player’s species and are not counted in the final population score.

How Will I be Graded?

Read the short version of the rules.


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