Overview

Asteroid is a two-player science fiction board game published by Game Designers’ Workshop (GDW) in 1980. A mad scientist has programmed a computer-controlled asteroid to crash into Earth, threatening an extinction-level event. One player assembles a team of adventurers (accompanied by Sasha the dog) who must infiltrate the asteroid’s cave system and activate the self-destruct sequence. The other player controls the asteroid’s robotic defenses, arranging the cave system and deploying traps to stop the infiltrators.

Components

• 8 Geomorphic cave tiles (assembling the asteroid’s interior)
• Character pieces (adventurers and Sasha the dog)
• Robot/defense pieces
• Dice
• Rules booklet

Setup

1. The defending player (Asteroid) secretly arranges the 8 geomorphic tiles to create the asteroid’s cave system.
2. The attacking player (Earth) selects their team of adventurers.
3. The Earth player places their team at the entry point of the asteroid.
4. The Asteroid player deploys robotic defenses within the cave system.

Turn Structure

Players alternate turns:

1. Earth Player Turn: Move adventurers through the cave system, exploring rooms and corridors.
2. Asteroid Player Turn: Activate robotic defenses, move defenders, and attempt to stop the adventurers.

Actions

• Move: Advance adventurers or robots through the cave system.
• Explore: Reveal new sections of the asteroid as adventurers enter them.
• Combat: When adventurers encounter robotic defenses, resolve combat using dice.
• Activate self-destruct: The Earth player’s ultimate objective is to reach and activate the asteroid’s self-destruct mechanism.
• Deploy defenses: The Asteroid player positions and activates robotic guardians.

Scoring / Victory Conditions

• Earth Player wins: If the adventurers reach the self-destruct mechanism and activate it, destroying the asteroid.
• Asteroid Player wins: If all adventurers are eliminated before they can activate self-destruct, or if time runs out.

Special Rules & Edge Cases

• Geomorphic tiles: The cave system is different every game since the defending player arranges the tiles secretly.
• Sasha the dog: A member of the adventurer team with unique abilities.
• Hidden information: The asteroid layout is unknown to the Earth player at the start.
• Time pressure: The Earth player has a limited number of turns before the asteroid impacts.

Player Reference

Earth Player: Controls adventurers; goal is to reach and activate self-destruct

Asteroid Player: Controls robotic defenses; goal is to stop the adventurers

Key mechanic: Secret map construction with geomorphic tiles