Overview

American Megafauna is a complex evolutionary simulation board game designed by Phil Eklund and published by Sierra Madre Games in 1997. Players begin as proto-dinosaurs or proto-mammals in prehistoric America after the Permian-Triassic extinction event. Through adaptation, speciation, and environmental survival, players evolve species that compete for ecological niches. The game incorporates real evolutionary factors including Milankovich cycles, dentition, biome shifts, and mass extinction events.

Components

• Game board (map of prehistoric America with biomes and habitat areas)
• Species counters and markers
• DNA cards (representing genetic traits and adaptations)
• Event cards (environmental changes, mass extinctions)
• Biome markers
• Player aids and charts
• Dice

Setup

1. Place the game board showing prehistoric America.
2. Each player selects a starting species (proto-dinosaur or proto-mammal archetype).
3. Deal initial DNA cards to each player.
4. Set up starting biomes and environmental conditions.
5. Place species tokens in starting habitat areas.
6. Determine first player.

Turn Structure

Each turn represents a geological time period and consists of:

1. Event phase: Draw and resolve event cards (climate changes, volcanic activity, asteroid impacts, biome shifts).
2. Auction/bidding phase: Players bid on available DNA cards representing new evolutionary traits.
3. Adaptation phase: Players apply acquired DNA traits to their species, modifying capabilities like dentition, size, speed, and behavior.
4. Speciation phase: Players may split existing species into new species, each with different trait combinations.
5. Population phase: Species populations grow or shrink based on habitat suitability and competition.
6. Extinction check: Species that cannot sustain themselves in their current biome are eliminated.

Actions

DNA Acquisition

• DNA cards represent evolutionary traits (herbivore dentition, predator adaptations, size changes, behavioral traits).
• Players acquire traits through auction/bidding.
• Traits determine how well a species fits its ecological niche.

Speciation

• Players can split an existing species into two, creating a new species with a different combination of traits.
• Speciation allows diversification across multiple biomes.

Habitat Competition

• Multiple species in the same biome compete for resources.
• The species best adapted to the current conditions survives; others may be displaced or go extinct.
• Wandering immigrant animals (non-player species) add additional competition.

Environmental Adaptation

• Biomes shift over time due to Milankovich cycles and other climatic events.
• Species must adapt to changing conditions or face extinction.

Scoring / Victory Conditions

Victory points are scored during periodic scoring rounds based on:

• Number of surviving species
• Size and diversity of species populations
• Control of ecological niches
• Species that survived mass extinction events

The player with the most victory points at the end of the game wins.

Special Rules & Edge Cases

• Milankovich cycles: Orbital variations cause regular climate shifts that change biome distributions.
• Mass extinctions: Catastrophic events can wipe out poorly adapted species en masse.
• Dentition: Tooth type is a key evolutionary trait determining diet and competitive advantage.
• Dinosaurs vs. mammals: The game pits these groups against each other, with each having different evolutionary advantages.
• Solitaire play: The game can be played solo.
• Successor game: Bios: Megafauna (2011) by the same designer is a more streamlined reimplementation.
• High complexity: The game is known for its scientific depth and steep learning curve.

Player Reference

Trait Category	Examples
Dentition	Herbivore, carnivore, omnivore teeth
Size	Small, medium, large body types
Behavior	Pack hunting, burrowing, migration
Adaptation	Cold tolerance, desert survival, aquatic

Core loop: Events → Bid on DNA → Adapt species → Speciate → Populate → Check extinction