Arkham Horror is a cooperative adventure board game designed by Richard Launius, originally published in 1987 by Chaosium.

While exploring city locations or other worlds, the investigators face random events which may benefit or harm them.

In the second edition, when the doom track fills, this typically begins a final opportunity for the players to directly defeat the creature and win; otherwise, they lose.

[3] Arkham Horror was one of several Lovecraft-based board games submitted by Launius, with other designs from the same period including 'The Trail of the Brotherhood', 'DreamQuests', and 'Imprisoned with the Pharaohs'.

Finally, Kevin Wilson at Fantasy Flight massively revamped the game, throwing out a roll-and-move system as well as other concepts and also expanding much of the gameplay.

In early 2011, Fantasy Flight released Elder Sign, a game based on Arkham Horror but which provides a much faster-paced alternative.

By streamlining many of Arkham Horror's mechanics and using dice to solve encounters, games of Elder Sign lasts 90 minutes on average, rather than 2–4 hours.

[7] The 1987 version of Arkham Horror has the following game components: a board map of the town of Arkham; 99 playing cards with various events; 50 monster counters; two 4-page investigator rules sheets; eight investigator cards; eight pawns; and markers.

There are several locations off the routes, such as Miskatonic University or Dark's Carnival, where a player's investigator may have encounters, or where a gate to another world may appear.

The investigator cards are pre-made, with four fixed attributes: Fast Talk, Fight, Knowledge, and Sneak.

These characters have three pairs of statistics to represent their strengths and weaknesses, and the ability to "slide" their current focus on each scale towards either extreme or keep it relatively average.

The back of each card includes a brief history for the character, in case players wish to add an element of roleplaying to the game.

The basic resolution mechanic is to roll a number of six-sided dice equal to the statistic, plus any modifiers.

Most checks only require a single success, with the general exception of Combat rolls when fighting monsters.

There are Skill cards that can be acquired, increasing a statistic by one as well as granting an extra bonus die when the player spends a Clue token on that particular type of roll.

If the monster is not immediately destroyed or removed from the board, they then roll Fight plus any bonuses from weapons, items or spells.

If the terror level rises high enough, stores begin to close and potential allies flee, and the Ancient One will awaken even faster once Arkham becomes completely infested.

Weather may make it more difficult to move through the streets or a rumor might require investigators to complete an action in a certain number of turns to prevent even worse effects from happening.

Even with seasoned players, simply setting everything up can take a while, and once you begin adding expansions, the amount of space you need to enjoy the game is increased."

It's only fun if you have a regular group of gaming friends who get don't mind learning something that's not immediately intuitive.

On June 11, 2021, a third expansion titled Secrets of the Order was released, this time taking players to the French Hill neighborhood and the underworld.

[18] In 2011, a series of novels were published under the Arkham Horror banner via Fantasy Flight Games, beginning with Ghouls of the Miskatonic by Graham McNeill.