Tabletop Game / Arkham Horror

Take that, see? Nyah!

"Searchers after horror haunt strange, far places."

— H.P. Lovecraft, The Picture in the House

Arkham Horror is an American-style Adventure Board Game based on H. P. Lovecraft's Cthulhu Mythos and taking place in the 1920s. It was designed by Richard Launius in 1987 for Chaosium and was revamped and re-released by Fantasy Flight Games in 2005. The players must cooperate as a handful of investigators trying to prevent the awakening of an Ancient One with the fate of the city of Arkham, and sometimes the whole world, in the balance. The investigators will collect ordinary and magical items, explore forgotten or forbidden regions of the town, battle monsters, enter alien worlds, and (per the setting) go gibbering insane in the process.

The game is fairly complicated and features a staggering amount of cards, markers, and counters. Three decks of standard size Ancient One cards are used for random encounters and events. Nearly a dozen decks of smaller sized Investigator cards track the possessions/status of the players. There are fistfuls of cardboard counters for health, sanity and money, monster markers, and other miscellaneous tokens. Success or failure is determined by a pool of six-sided dice; every roll of five or six counts as a success, but modifiers can add or subtract from the dice pool for your roll and difficult tasks can require multiple successes.

Investigators are the player characters. Each investigator has scores for stamina and sanity, some set and random starting items, and a special ability such as healing or extra income. They also have a collection of linked and adjustable attributes, so raising one stat will lower its counterpart. For example, you can move faster at the expense of stealth to speed through the town on one turn and next turn change scores to sneak past the monster guarding your destination at a snail's pace.

The Ancient One is a powerful, alien monster featured in the Cthulhu Mythos, including Cthulhu himself. Each Ancient One has a character sheet akin to an investigator which includes special rules that modify the game as a whole (such as ongoing harmful weather), rules modifying its favourite monsters, and combat stats should it awaken. One is randomly drawn to be your antagonist for the game and the players ultimately race against time to prevent its awakening. Almost every turn a counter will be added to the doom track. When full, it awakens and the investigators have one last chance to defeat it. There are very few ways to slow the doom track down and many to speed it up. It also serves as a “health” meter during the fight. Ancient Ones are horribly powerful in combat, often resistant or immune to forms of damage and usually able to kill unlucky investigators who fail to meet specific requirements before combat even begins.

The game is played on a large board depicting Arkham city (no, not that one) and divided into neighbourhoods with multiple locations within them. Random encounters can occur at almost any location in the game and the encounters range from paranormal horror to mundane accidents. Some areas provide set beneficial effects that allow the players to shop, heal, or learn new skills. On the long side of the board are the other world locations representing alien dimensions like Yuggoth or lost terrestrial regions like the Plateau of Leng. Investigators must brave the other worlds to seal the portals; while they generally don't encounter monsters while doing so, they often face other threats to their health and sanity.

Mythos cards control the flow of the game. One is drawn at the start of each turn. A mythos card will open portals, move monsters, reveal clues, and activate other events that can hinder or help the investigators. Portals open in unstable locations and release monsters. Having too many open portals can awaken the Ancient One early. Portals can only be closed after slowly exploring the other world linked to it, and in most cases, they can be reopened later in the game. Every new portal brings at least one new monster to the city. Monsters move randomly based on a series of black and white arrows on the game board and the mythos card drawn, and some also have special movement rules such as being able to fly. While you can attempt to evade monsters with stealth, they must ultimately be dealt with; having too many monsters in play is not only dangerous and obstructive, but will advance the terror track. The terror track measures the level of fear in Arkham’s residents, and the higher the track advances, the fewer services and allies will remain in town.

Eight Expansion Packs have been produced for Arkham Horror second edition. Four of them are larger expansions with new boards representing other cities in New England, a host of new investigators, Ancient Ones, and monsters. They're also almost as expensive as the original game. The four smaller expansions feature a few new rules, monsters, and additional cards in the base game. A major new rule spanning the expansions is the addition of the Herald, a powerful monster acting against you and serving as the Ancient One's Dragon. A later expansion adds Guardians, which are beings and/or organisations supporting (or at the very least being on roughly the same side as) the Investigators.

Expansion Details

Curse of the Dark Pharaoh: Small expansion. An exhibit of Egyptian artefacts has arrived in Arkham and is stirring up trouble.

• Exhibit items: Similar to unique items but can only be received through random encounters.
• Barred from the neighbourhood: A combination of offending the locals or a traumatic experience on your end prevents you from entering locations in a given neighbourhood.
• Benefits and detriments: Some new special effects that can be attached to your character.
• Dual-color Gate cards: Double-duty random encounters for other world events.

In 2011, a revised edition was released. Among the changes:

• The Exhibit Items, Spells, Allies, Benefits, and Detriments had their effects overhauled.
• The Barred from Neighbourhood mechanic was replaced with Patrol markers.
• The Ancient Whispers marker and Exhibit Encounter deck were added to provide an additional and more certain method of obtaining Exhibit Items.
• The inclusion of the Dark Pharaoh Herald.

The Dunwich Horror: Large expansion. In a rural town outside of Arkham, a family of sorcerers have created an abomination that threatens mankind. Adds eight investigators, four Ancient ones, and two other worlds.

• The Dunwich Horror: An extremely powerful monster that can be summoned during the game. The Horror can randomly advance the doom track and has randomly drawn abilities and combat stats per battle.
• Injury and madness: Being reduced to zero stamina/sanity now has a lingering effect. Injured/insane investigators can be retired to allow the player to draw a fresh character.
• Conditions: These are ongoing effects that have "toggle" conditions and can activate/deactivate continuously during the game.
• Stalker monsters: Sneaky monsters which can directly pursue nearby investigators, even ignoring the boundaries that limit monster movement in the process.
• Tasks and missions: Lengthy side quests may be taken to gain rewards, missions also require sacrifices to complete.
• Vortices: Special locations in Dunwich of dimensional instability. Monsters will enter them to advance the terror track and to summon the Dunwich Horror.

The King in Yellow: Small expansion. A charity performance of the infamous play, The King in Yellow, will be performed in Arkham, driving the populace mad and destroying the town.

• The King in Yellow: The play is performed in three acts; reaching the third act ends the game. The first two will randomly occur based on new Mythos cards unless the investigators pay the cost of preventing it.
• Magical effect cards: These keep track of ongoing spells cast on your investigator.
• The Herald rules were introduced in this set. The Herald changes the game much like having a second Ancient One in play. The first Herald, the King in Yellow, forces you to choose between adding Blight characters into play or advancing the Doom track under certain conditions.
• Blight: These characters have gone mad from the play and serve as anti-allies to hinder you.
• Spawn monsters: These are monsters that only enter play under specific conditions.

The Kingsport Horror: Large expansion. Mythos-related problems are starting in nearby Kingsport, however, there are friendly powers intervening for humanity. Adds eight investigators, four Ancient Ones, two other worlds, and two new heralds.

• Guardians: Three benign entities are aiding mankind.
• Aquatic monsters: These monsters can directly move from aquatic locations to attack investigators.
• Elusive monsters: These monsters try to avoid investigators
• Rifts: These are mobile Gates that might open during play. Once open they move across the board spawning monsters and possibly advancing the doom track.
• Epic Battle rules: These are randomly drawn events that change how the battle against the Ancient One plays.

The Black Goat of the Woods: Small expansion. The cult of Shub-Niggurath is rising in power and must be stopped.

• Corruption: Exposure to the Mythos now causes horrible mental and spiritual decay to investigators.
• Gate bursts: Gates that have been sealed can be forced open again. This, however, doesn't advance the doom track.
• Cult membership: You can infiltrate the One of the Thousand Cult and experience new encounters.
• Difficulty levels: optional cards give guidelines on altering the difficulty of the game.

The Innsmouth Horror: Large expansion. This town is directly under the control of Mythos forces and its Deep One masters are making their move for power. It introduces sixteen new investigators, eight new Ancient Ones, two new heralds.

• Innsmouth: The town is an enemy base and investigators will have to evade the police while exploring the area or suffer harsher consequences.
• The Innsmouth Look: The town is home to human/Deep One hybrids, possibly including the investigators!
• Deep One uprising: The Deep One conspiracy in Innsmouth is represented by a new countdown track. If the track fills, their efforts have succeeded and the Ancient One awakens independent of the Doom track. The investigators can slow the uprising track by alerting the FBI.
• Personal stories: Investigator backstories now come into play with personal goals to meet.

The Lurker at the Threshold: Small expansion. It's realised that the portals opening through Arkham are extensions of Yog-Sothoth, and it must be confronted to save the city.

• Dark Pacts: Your investigator can make deals with the Lurker for power and aid. Until the Lurker decides to collect on your debts.
• Relationships: Investigators now draw cards that give shared background and benefits with another player.
• New Gates: Gates will have new special abilities to spice things up; from movement to sharing other worlds, to advancing the doom track.

Miskatonic Horror: Large expansion. A discovery at Miskatonic University has created new mysteries concerning Arkham's dark days. Unlike other large expansions it doesn't add a new board, new rules, and new features to the game, rather it builds on the additions from other expansions by adding more cards to the pools (such as new exhibits and cult encounters).

• Institutions: One new feature is gaining the help of "friendly" (at least non-Mythos) organisations.

Fantasy Flight also produced many spin-offs. Among them are:

• Mansions of Madness: Players investigate an Old, Dark House (one of many possible ones) while one player designated as the Keeper controls the opposition. Sort of a lite-version of roleplaying Call of Cthulhu. Has received two large expansions. Forbidden Alchemy introduces a new puzzle type as well as three new scenarios with a Mad Science angle. Call of the Wild features five new scenarios with an outdoors locale as well as non-linear gameplay. There are also six single scenario expansions: Season of the Witch, The Silver Tablet, Til Death Do Us Apart, House of Fears, The Yellow Sign, and The Laboratory (the last one requires Forbidden Alchemy). The second edition of the game introduces a mobile device app which, among other things, eliminates the need for a Keeper player.
• Elder Sign: A Dice-based game where you complete adventures at a Museum of the Strange and Unusual to gain the needed amount of Elder Signs to prevent an Eldritch Abomination from awakening. Essentially a scaled-back version of Arkham Horror. The shortest of all the games, with average playtime around 45 minutes. Currently has four main expansions and a POD mini-expansion: Unseen Forces, which brings many new ancient ones and investigators to the game, Gate of Arkham, which has the action spill out into the greater Arkham area, Omens in Ice, which revolves around an expedition to the frozen wastes of Alaska, Omens of the Deep, which involves a voyage around the South Pacific, and Grave Consequences, a small Print-On-Demand expansion that adds three new gameplay features: Phobia, Epitaph, and Epic Battle cards. A mobile platform adaptation called Elder Sign: Omens is also available.
• Eldritch Horror: Involves investigating sinister happening on a globe-trotting scale, with a definite Indiana Jones-vibe to it all. Definitely the closest to the original game, but here the focus lies in solving "Mysteries" (though closing gates is still important). While still large and epic, it is more streamlined and fast paced compared to Arkham Horror, with average playtime at 2-4 hours (compared to 4+ hours). Has received several expansions, adding all of the characters from the game.
• Arkham Horror: The Card Game: A living card game using many of the same characters and concepts. Unlike the usual LCG format, the game is cooperative with players building decks to defeat a scenario where threats come from an "Encounter Deck." Multiple expansions have been released.
• Arkham Horror: Final Hour: A more fast-paced Hold the Line style of game, taking place in Miskatonic University, where monsters have completely overrun the place and The End of the World as We Know It is nigh. Has a fairly short runtime and relatively simple rules, with more of a combat focus than the others.

Fantasy Flight has also started publishing tie-in novels, including two trilogies:

Novel details

• The Dark Waters Trilogy by Graham McNeill
  • Ghouls of the Miskatonic
  • Bones of the Yopasi
  • Dweller in the Deep
• The Lord of Nightmares Trilogy
  • Dance of the Damned by Alan Bligh
  • The Lies of Solace by John French
  • The Hungering God by Alan Bligh and John French
• Feeders From Within by Peter J. Evans
• The Sign of Glaaki by Steven Savile and Steven Lockley
• Wrath of N'Kai by Josh Reynolds
• The Last Ritual by SA Sidor
• Mask of Silver by Rosemary Jones
• Litany of Dreams by Ari Marmell
• The Devourer Below (anthology)
• Cult of the Spider Queen by SA Sidor
• The Deadly Grimoire by Rosemary Jones
• Lair of the Crystal Fang by SA Sidor

A third edition was released in 2018. It significantly retools the game and introduces many mechanics from the various spinoffs; in particular, every play session is based around a given scenario with its own story, and the story can play out in a number of ways depending on what the investigators do.

Asmodee Digital announced Arkham Horror: Mother's Embrace, a turn-based RPG with an original story and similar mechanics to those found in the tabletop games. It was released on March 23, 2021.

Arkham Horror can be found here. Fantasy Flight gives outstanding support to the game, including .pdf files of all rulebooks, new Heralds and investigators, and rules for tournament/league play.

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Arkham Horror shares many tropes with the greater Cthulhu Mythos. The board game directly features examples of:

The game in general

• Advancing Boss of Doom: In the 3rd edition Tsathoggua scenario, the Ancient One starts to consume the game board from one end to the other. He can be defeated before he finishes, but any investigators in a neighbourhood when it's devoured are automatically killed for good.
• A.K.A.-47: Most of the guns go by generic names such as ".45 automatic" or "rifle". There is an exception in the tommy gun, though "tommy gun" is technically only a nickname.
• Anti-Frustration Features: If an Investigator uses an Elder Sign to seal a gate, which costs them 1 stamina and 1 sanity, the Elder Sign still seals the gate even if the Investigator is knocked unconscious (0 stamina) or driven insane (0 sanity).
• Armor-Piercing Attack:
  • Zoey Samaras may ignore any Resistances on monsters or Ancient Ones. Any Immunities are instead treated as Resistances.
  • Professor Armitage, an ally, provides a permanent bonus to Lore and allows you to ignore Magic Resistance.
  • Richard Upton Pickman, an ally, provides a permanent bonus to Luck and Speed, and allows you to ignore Physical Resistance.
• Artistic License – History: A minor, easily missed one, but it should be noted anyway. One of the Arkham Asylum encounters in Innsmouth Horror has you sneaking into a finger-painting session. Finger-painting is indeed used as a component of mental therapy at times, so that's done right. The problem? Art therapy in general dates only to the late 1940's, with finger painting as a later addition to the milieu. Finger painting itself dates to prehistoric times, but it wasn't part of art education until the 1930's.
• Asskicking Leads to Leadership: If you kill enough monsters and/or seal enough gates, you can be appointed deputy of Arkham.
• Authority Equals Asskicking: It is unclear what position in city politics that Charlie Kane holds, but either way, getting him re-elected to that position via his personal story gets him some nice benefits.
• Ax-Crazy: Most cultists are after power and favour from their Ancient One. Cultists of Azathoth serve a mindless, universe-ending patron and have nothing to actually gain from it. The game also includes actual maniacs armed with axes as common low-level enemies. They become slightly stronger when playing against Azathoth.
• Barrier Change Boss: Zhar is technically not one, but two Ancient Ones: Zhar and Lloigor (it was probably called by the former's name only to distinguish from the "Lloigor" enemy). Zhar has Magical Immunity, but once he gets defeated, you must face Lloigor, who has Physical Immunity instead.
• Bedlam House: The infamous Arkham Asylum. The original Arkham, not that other one. Investigators actually may receive treatment here to restore lost Sanity (and automatically do so if (or when) they are driven insane), or search here for some valuable clues.
• BFG: The elephant gun, a Real Life example, and a powerful physical weapon in the game. Real elephant guns were frequently custom-made firearms, and in-game you have to pay every time it's refreshed — even the flamethrower can be refreshed at will!
• Big Bad: Whichever one of the Old Ones or Outer Gods gets chosen during the prep phase is the overall main antagonist.
• Blob Monster:
  • Formless Spawns are, well, formless mass of some black... thing.
  • Abhoth and his "Childs" are big, hungry blobs of grey goo.
  • Yib-Tstll is big blob of... something, with countless eyes.
  • Nyogtha is a formless black mass with countless tentacles.
• Boss in Mook Clothing: Any Mask enemies have either very strong stats, dangerous abilities (like devouring an investigator who fails any skill check against this monster), or both. And they may spawn like normal monsters, through encounters, gates, or mythos. Fortunately, you only must face them when playing against Nyarlathothep.
• Broke Your Arm Punching Out Cthulhu: You can beat him, for now, but how many investigators went mad or died in the process?
• Brown Note:
  • Many random encounters, especially in unstable locations or Other Worlds, have devastating effects on investigators' Sanity, just by sheer "wrongness" of situations or places.
  • Reading occult books is harmful to your Sanity, too.
  • The King in Yellow expansion has the eponymous cursed play, which drives the inhabitants of Arkham insane.
• Brown Note Being: Most monsters are dangerous not only to the health, but also to the sanity of the investigators, requiring a Horror check to avoid taking damage. Some monsters are actually only dangerous because they deal heavy Sanity damage, and otherwise have low Stamina damage.
• Canine Companion: Duke is one of the allies in core game. He increases your maximum Sanity. Ashcan Pete starts with him by default.
• Cast from Sanity: Many spells and occult books have a Sanity cost to play, as does the use of Elder Signs to close and seal planar gates; in the Cthulhu Mythos, that sort of thing draws on higher orders of reality than the human mind can comfortably process — like the ones the Eldritch Abominations come from.
• Cat Girl: Bast, the cat-headed Egyptian goddess who serves as a guardian in Kingsport.
• Chest Burster: Eihort infects investigators with his younglings, which are represented by Brood tokens. Each time an investigator receives one, (s)he must roll a dice; if the result is lower than number of Brood tokens, the investigator is devoured. Outside of the final battle (where Eihort uses this as his main form of attack), investigators gets infected each time they seal a gate or defeat cultits.
• City of Adventure: Arkham, home to the famous Miskatonic U., a number of dangerous cults, and many eldritch locations. With expansions, Arkham also plays home to Brown Note plays or cursed exhibits.
• Classy Cat-Burglar: Ruby Standish is an ally who improves your Sneak and gives you a unique item from her haul.
• Clock of Power: In the 3rd Edition, The Pocket Watch is an equippable item with the Simple, yet Awesome effect of granting the owner an extra action every turn.
• Colour-Coded for Your Convenience: Monster tokens have differently coloured edges, depending on their movement rules.
  • Black-coloured ("normal") monsters follow standard rules. Most monsters belong to this type.
  • Red-coloured ("fast") monsters move like normal monsters, but do two moves instead of one, allowing them to quickly patrol the streets of Arkham; they will stop if they meet an investigator on their first move.
  • Yellow-coloured monsters do not move at all, which means they nearly always stay in the locations they spawn in (usually a gate). They often have particularly nasty stats, which makes them good portal guardians.
  • Blue-coloured monsters can fly, in order to more freely attack investigators. If they fail to find a suitable target, they will move into sky, becoming unreachable, until the next opportunity arises.
  • Green-coloured monsters always have some unique movement rules stated on their reverse side. For example, chtonians, instead of normal movement, will roll a dice, and on a specific result, will damage every investigator in Arkham.
  • Expansions also introduced purple-coloured monsters ("hunters") — monsters who specifically pursue investigators instead of moving like usual (essentially a hybrid between normal and flying monsters); and orange-coloured ("aquatic") monsters — monsters able to use aquatic locations to cut corners to reach their victim.
• Combat Tentacles:
  • Nyoghta spawns its tentacle instead of random monsters during random encounters. The investigator must defeat it under three turns, or die.
  • Zhar uses them to first grab one hand of the current first player, then kill them off on next turn. In some of its Sinister Plots, they are used to directly smash investigators.
• Conjoined Twins: Zhar/Lloigor Ancient One(s), enormous tentacled beasts. Unfortunately, they have separate health bars (22 Doom tokens in total!), which, combined with them being a Time-Limit Boss, makes them particularly frustrating.
• Continuing is Painful: Losing all your Stamina or Sanity points doesn't end the game for your Investigator, it just sends them to the hospital or asylum, respectively (or, if this happens in an Other World, they get temporarily Lost in Time and Space). However, they lose half of their items and Clue tokens. In later supplements, you can opt to take an Injury or Madness instead, but these cripple them for the rest of the game.
• Cool Gate: Portals are more horrifying than cool, though.
• Crowbar Combatant: A decent weapon that can be discarded to attempt some breaking and entering for common items.
• Cult: Your human opponents are members of the cults implied to be responsible for the whole mess. The specific cultist monster is often modified by the Ancient One in play with anything from having unlimited numbers to advancing the Doom track if killed.
  • Explicitly averted with Abhoth, who has no servants amongst humans. Whatever caused its awakening, it is of no human origin.
• Damage Reduction: Seen in different forms through the game, on both sides of the conflict:
  • The mobster Michael McGlen takes reduced Stamina damage, while professor Harvey Walter takes reduced Sanity damage.
  • Some spells and unique items have similar effects for any investigator. Food and alcohol can be consumed instead of 1 point of Stamina/Sanity damage, respectively.
  • Chaugnar Faugn can't lose more than 3 Doom tokens during one turn; any excessive damage is ignored. Considering that he is a Time-Limit Boss, this may be frustrating.
  • Ghatanothoa ignores 1 success from each investigator's attack.
• Deal with the Devil:
  • The Lurker at the Threshold offers these, giving power to the investigator bold enough to claim it.
  • The Dark Man of Wizard's Hill is a very helpful individual, but eventually the debt will come due...
  • In 3^rd Edition, some events offer an investigator a Dark Pact in exchange for some major benefit (sometimes survival). The Pact has a 1-in-6 chance of coming due at each Reckoning, and only then is the cost revealed — which can be anything from instant death to a flood of monsters.
• Death from Above: Without an adjacent investigator to attack, a flying monster is allowed to move into the sky location. Once in the sky, they are allowed to swoop down on an investigator in any street location.
• Death Is a Slap on the Wrist:
  • Being reduced to zero Stamina or Sanity sends you to the hospital/sanitarium. You will lose half of your items and clue tokens, but you get to choose which ones and you round down. If you somehow lose both at the same time, on the other hand, you get devoured.
  • With the Dunwich Horror expansion, you can even get around the item/clue loss by accepting, as appropriate, an Injury or a Madness. For many players, the nuisance supplied is more than outweighed by the kept items and clues (especially the clues). Just... be careful about taking multiple ones, since if you're anyone other than Rita Young, getting a duplicate of an Injury or Madness you already have results in your devouring.
• Dice Roll Death:
  • Many encounters forces investigators to pass skill checks or suffer various penalties; in some cases (mainly in the Other Worlds), consequence of a failure is immediate death.
  • While imprisoned in Innsmouth, some encounters outright kills investigator (they gets fed to a shoggoth). As encounters are always random, you can never know wether you'd survive another night here.
• Did You Just Punch Out Cthulhu?: You can literally do it. (To Cthulhu, at least, and to most of the other possible Eldritch Abominations as well, with the notable exception of Azathoth.) You're gonna have a hell of a time doing it, though.
  • The Curse of the Dark Pharaoh expansion has encounter cards where you fight an Ancient One by yourself. And, yes, one of the ones you can fight is Cthulhu.
• The Dragon: A Herald is an eldritch being directly trying to summon the Ancient One and working against the players. Adding a Herald to the game is akin to adding a secondary Ancient One, as they have a major impact on the game and add many new challenges.
• Dream Land: The Dreamlands are one of the other worlds you can visit. By most other world standards, they're a very nice place.
• Dual Wielding: Can be done, if the weapons or spells in question only require one hand each. Two-handed weapons are more powerful, but you can only use one at a time.
• Duel Boss: The Curse of the Dark Pharaoh expansion has encounter cards where you fight an Ancient One alone, without help from other investigators (even if it is not the current Big Bad; though if it is, the battle will be slightly easier, since it will start with reduced Doom). Success in the battle allows you to immediately seal the gate and take it as a trophy, as well as providing satisfaction from singlehandly kicking Cthulhu's (or whoever you faced) ass.
• Dump Stat: The dump stat can change during the course of the game, but it's always risky. Each stat is inversely linked with another; thus, for instance, raising your Fight will lower your Will, and you can't kill the monster if just seeing it drives you insane. Luck of the draw and strategy factor heavily in Arkham Horror; having the right items can mitigate the risks of having a dump stat, and you can change it as the situation demands.
• Dungeon Bypass: There are a few methods to skip turns spent exploring the other world; the sooner you escape, the better your chances of sealing portals and maybe winning a game.
• Egyptian Mythology: Bast, the cat goddess, serves as one of the guardians. For a price, you can play a Kind Hearted Cat Lover and feed strays to receive her blessing. Her blessing regenerates Stamina or Sanity each turn and protects you from being devoured.
• Eldritch Abomination: Your many opponents, including, of course, any Ancient Ones.
• Eldritch Location: The other worlds.
• The End of the World as We Know It: Lesser Ancient Ones like Yig can probably only destroy Arkham itself. Great Cthulhu could end the world. Yog-Sothoth and Azathoth are more than capable of destroying the earth, Azathoth to a degree that the game ends with no boss battle if he awakens.
• Enemy Mine: It's possible to have a group of investigators containing a federal agent, a gangster, a rookie cop, and a bootlegger. And have one of them become deputy of Arkham. Presumably, the threat of the Ancient One dwarfs petty human crime.
• Energy Weapon: The Yithian rifle. It feeds on your Focus to refresh.
• Everyone Has a Special Move: Every investigator has at least one unique ability, which makes playing each of them a different experience. Investigators from core game are for the most part are rather generic (though there are exceptions), but expansions introduced more exotic ones.
• Evil Takes a Nap: The investigators are trying to prevent an Eldritch Abomination from awakening and ending the world. The Ancient One's ongoing effects on the game world are merely it "stirring in its slumber", and if it does start to wake up, they face a hellish fight to knock it back out before it can regain its full power.
• Face–Heel Turn:
  • The "Joining the Winning Team" mission requires you to sacrifice allies to betray the other players and win the game for yourself.
  • One of Nyarlathothep's Sinister Plots allows one (and only one) of the investigators to join Nyarlathothep. This eliminates the betrayer from the fight and makes Nyarlathothep stronger for the duration of the fight. The betrayer wins if his former teammates get defeated, but if they win, he dies and becomes the only loser.
  • In one 3rd Edition scenario from "Secrets of the Order", the investigators may be offered the choice to seal away the Ancient One in the usual way or improvise their own method by studying from dark powers. The latter ending strongly implies that the investigators have become thralls of Yog-Sothoth and specifically excludes from the victory anyone who hasn't made a Dark Pact.
• Fighting a Shadow:
  • Nyarlathotep in spades. He's the Outer God who directly interferes with man and has "a thousand" forms. He's simultaneously an Ancient One, a herald, at least five separate monsters with the base game, and possibly ten with all expansions.
  "It was then that I remembered a terrible thing. Nyarlathotep had a thousand faces with which to battle us — all at once if he so chose."
  • Yog-Sothoth as well: Ancient One, Herald (the Lurker at the Threshold), and he is every gate in the game.
• Final Boss: The Ancient One is this. It's possible to win without having to fight it, but letting it awaken and then kicking its ass is also a victory condition. Just don't try that on Azathoth, and for other Ancient Ones, not only is victory going to be quite unlikely, but even if you do win, it'll probably be at great cost.
• Fire-Breathing Weapon: A flamethrower was added in the Dunwich expansion.
• Five-Finger Discount: One street encounter in 3^rd edition has an unattended display of apples for sale. If you eat some without leaving money, you need to pass a Will test or literally be Cursed by your own guilty conscience.
• Fortune Teller: One of the allies in the core game, Anna Caslow, is a fortune teller. She provides a permanent bonus to Luck, and gives 2 bonus clue tokens on joining.
• Giant Spider: Leng Spiders; the small ones are pony-sized.
  • Atlach-Nacha, the horrifyingly-powerful Ancient One and King Mook to the aforementioned Leng Spiders.
• Guns Akimbo: Anyone, if you have two one-handed weapons. Joe Diamond, Jenny Barnes, and Tony Morgan have it on their character portraits.
• Half-Human Hybrid:
  • Deep One Hybrids are monsters from Innsmouth, men with horrible inhuman features. Investigators in Innsmouth run the risk of drawing Innsmouth Look cards and discovering that they too are hybrids.
  • There are also two investigators, Amanda and Silas, who are already known to be hybrids. Whether or not they discover this fact affects how their personal stories go.
• Helpful Mook: Nightgaunts, servants of the alien and somewhat benevolent Nodens. When you lose a battle against them, they drop you into the nearest gate. This can cause you to explore other worlds faster or get to gates that are otherwise blocked.
• Heroic Sacrifice:
  • The "For the Greater Good" mission involves getting your investigator devoured to win the game for everyone else.
  • Tommy Muldoon, the Rookie Cop, benefits other investigators if he is sacrificed as quickly as possible.
  • Silas Marsh can perform a heroic sacrifice (defying his Half-Human Hybrid heritage) to seal a gate.
• Holy Hand Grenade: Holy water is a powerful one-shot magical weapon.
• Hopeless Boss Fight: While there are no outright unbeatable Ancient Ones (Azathoth doesn't count, since there's no boss battle at all), some of them can have different starting conditions in the last battle depending on your performance, which sometimes may be so ungodly unfair, you may only be saved by some miracle (or really good preparations, so you may deal with them on the first turn).
  • Hastur increases his battle rating the higher the current Terror level is. If it's maxed out, he starts with a whopping (-10), quite potentially leaving you unable to even scratch him without clues. Lots of clues.
  • Glaaki is a Time-Limit Boss, and the exact time you have depends on the Terror level (if Glaaki ends his turn on level 10, it's game over). If you played particularly badly (Glaaki increases the Terror level by 2 each time an investigator is devoured), you may start at that value.
  • Shudde M'ell, instead of attacking, discards one unused Rubble token; if he can't, that's game over. As with Glaaki, you can start with none left to spare.
  • If Bokrug awakens with all four Beings of Ib intact, you would have to deal with a boss who has a battle rating of (-8), a full set of immunities, and 18 Doom tokens... under four turns.
  • Quachil Uttaus does not have a check for its attack. Instead, once per turn, it instantly kills the first player (who is assigned at the start of the turn). It doesn't have a terrible combat rating (-3) but it does have physical and magical immunity, and it forces you to discard all ally cards at the start of the fight. If you're playing Solo and it goes first, you instantly lose the fight, and if your team consists of a lot of low-Fight characters with few to no skills, you may end up with characters who cannot deal any damage without clue tokens, turning your entire team into dead weight.
  • You cannot deal more than three damage to Chaugnar Faugn in a single combat, and successes are not rolled over. Additionally, you have to discard either 3 clue tokens or 1 ally. This means, at a minimum, players need a combination between 12 clue tokens and 4 ally cards, and cannot spend Clue Tokens or risk being killed when unable to discard. The entire team can tell if they're dead before they even start.
  • If Thathoggua attacks first and the players have 1 monster trophy (or less) and no gate trophies, then their investigators instantly die. This isn't dealt to one investigator per attack; the entire table has to pass this check per turn or be devoured, so it's possible for the fight to end just as it begins.
  • Having less than three Clue Tokens, Monster/Gate trophies, and Items guarantees losing right away during Abhoth's attack. Going into the fight, it's already apparent if it's over.
• Hostile Weather: Weather mythos cards temporarily (until they get overwritten by other Process cards) change conditions in Arkham (usually in the form of penalties to one skill check and bonuses to another).
  • When playing against Ithaqua, any Weather cards' effects are disabled, but instead investigators must deal with deadly frost, which will damage any investigator who stays on the streets during the Mythos phase.
  • When playing against Cthugha, any Weather cards' effects are disabled, but instead investigators must deal with deadly heat, which will damage any investigator who spends more than 3 move points in one turn (except for using tomes).
• Hyperactive Metabolism: An interesting variant – food does not function as a healing item; it instead reduces stamina loss.
• I Can Still Fight!: An investigator can accumulate a full spectrum of injuries and madnesses, but unless they accumulate two matching ones (which is fatal), they may still fight (though obviously it would be more difficult, since many of them are quite debilitating).
  • Rita Young's special ability allows her to ignore a second copy of any injury/madness.
• Immune to Bullets: It depends on the monster. Some are as fatally allergic to bullets as people, while others will eat lead and then you as dessert.
• Increasingly Lethal Enemy: If an Ancient One is not an outright Time-Limit Boss, it is usually this.
  • All Ancient Ones from the core game (except for Cthulhu and Azatoth) gradually increase the difficulty of the "saving throw" against their attacks.
  • Y'Golonac increases damage with each turn.
  • Eihort adds one Brood token to each investigator at the start of the battle, and then adds one more to the current first player with each turn. Due to how Brood tokens work (each time an investigator receives one, they must make a die roll, and if the result is lower than the number of tokens, they are devoured, this time in the literal sense too). It becomes harder and harder to survive each time, until the seventh token becomes guaranteed death.
• I Need a Freaking Drink: Whiskey helps reduce Sanity loss.
• Instakill Mook: If an investigator fails a combat or evade check against a Servitor of the Outer Gods, they are instantly devoured.
• Intimidating Revenue Service: For Michael McGlen, the IRS might just be an even greater threat than the eldritch horrors invading Arkham. If he ever receives more than $5, he'll be found guilty of tax evasion, fail his personal quest, and be stripped of all money for the rest of the game, crippling his performance permanently.
• Ley Line: The ley line map allows an investigator to circumvent environmental effects caused by Mythos cards.
• Loads and Loads of Rules: The game has rules allowing you to fight monsters, cast spells, go crazy, go shopping, get lost between dimensions, go crazy, join the police, watch the stores close as people leave town, and go crazy before being eaten by an alien super-being. The expansions add more rules to the game to boot, including adding a The Dragon to work against you or allowing for pacts with the monster.
• Lovecraft Country: The game's setting, of course.
• Lovecraft Lite: It is perfectly possible, though difficult, to seal or defeat the Ancient One with no one going mad or dying.
• Loyalty Mission: Each investigator has a Personal Story related to his/her backstory and their personal problems and insecurities. If they succeed, they receive various boons, often quite strong, which makes them even more effective; but if they fail, they receive various penalties, up to and including to being totally screwed, sometimes even in fatal ways.
• Luck-Based Mission:
  • Quite a few of the Personal Stories are like this, and may be screwed either by unlucky dice rolls, or very unfortunate encounters or mythos cards; this is only made worse since some of them are timed as well. The consequences for losing can be anywhere from fatal to borderline nonexistent.
  • The entire boss fight with Yibb-Tstll is this. When she attacks, each investigator must roll as many dice as they have Focus; if they roll no successes, they die; if they roll at least two, they get Blessed (making it easier to fight her). So, depending on your luck, you may either curb-stomp her, or be completely slaughtered on the first round.
  • Same as above is the boss fight with Nyogtha. Once it attacks, the only thing which determines if you survive or not is one die roll; fail, and it's a One-Hit Kill, succeed, and you survive unscarred.
  • Ghatanothoa has a mechanic wherein anytime an Investigator gains 2 or more tokens simultaneously, they must flip over a face-down visage token. If the token has only an image of a sky, they survive. If it has Ghatanothoa's face on it, they are devoured immediately (thankfully the ten tokens reset when five are flipped). One of Ghatanothoa's Sinister Plot Cards has it flee into tunnels and every surviving Investigator has to flip over one of the ten tokens until only one remains and everyone survives or an unfortunate Investigator flips over the wrong one (killing that investigator instantly).
  • During play against Quachil Uttaus, the first player token does not move to the next player unless said player spends a clue token to give it away. This doesn't sound so bad, but if the token isn't passed, then during that turn the first player has to draw from the Dust Deck. If one of the four cards from Deck 1 is drawn that discards all of Deck 1. Next turn, you draw from 2 (and the same is true of Decks 2 to 3). However, one card in Deck 3 instantly kills the player who draws it. The decks are reshuffled back, and the token moves to the next player regardless. You can also take Sanity damage this way if you're unlucky from the various card draws, and the death in Deck 3 is inevitable as Deck 3 doesn't have a reshuffle card like 1 and 2.
• Luck Manipulation Mechanic: "Clue Tokens" represent various bits of Mythos-lore the characters have learned through their combing of the city. Spending a clue token after a die roll lets you roll an additional die, and you can continue to roll as long as you have tokens to spend. Some Skills even add 2 dice instead of 1 per token to certain kinds of rolls (Joe Diamond has this ability by default; it stacks with any such Skills).
  • The reason why Mandy Thompson is so broken is that she lets 1 investigator per round re-roll all failed dice.
  • Yig, on the start of his boss battle, instantly Curses all investigators (if they are already Cursed, they die). Curse makes all dice results instead of "6" count as failures, until it gets lifted (which is itself a Luck-Based Mission). Without it, he is relatively straightforward.
    • One of his Sinister Plot cards allows him to use this again, which may lead to a Total Party Kill if the investigators failed to remove the original Curse in time.
• Lucky Rabbit's Foot: A common item that is exhausted for a +1 Luck bonus.
• Magical Star Symbols: The Elder Sign from the Mythos is depicted as an off-kilter pentagram with a central eye. Mechanically, it acts as a powerful Protective Charm against otherworldly forces.
• Magic Knight: There's no equipment restrictions; each investigator may use any item or spell, and if they so wish, may easily take a gun in one hand and a spell in another. Though some are still better at one role or another.
• Maximum HP Reduction: When playing against Cthulhu, each investigator start with both their max Sanity and max Stamina reduced by 1. This is also his main form of attack in the last battle.
  • Besides Cthulhu, there are different ways to reduce (or sometimes even raise) your max Sanity and/or Stamina. Most of them are related to Personal Stories.
• Mini-Boss: The titular Dunwich Horror. If you can't prevent its arrival, then a seemingly normal monster tile is added to the game. One with a laundry list of special rules. The Dunwich Horror has tons of health, can advance the Doom track, and has a deck of cards that randomizes its combat stats, drawn after you enter combat with it. On one turn, it takes half damage and destroys all your gear; on the next, it has no special resistances but instantly kills you. Defeating it gives you any card you wish as a reward.
• The Mole:
  • Any investigator may join the the Silver Twilight Lodge or the cult of Shub-Nuggurath in hopes of acquiring something useful for the mission against Ancient One. This may backfire, though.
  • Diana Stanley starts with Silver Twilight Lodge membership by default, and can't lose it. Her Personal Story depends on how successful she is at this role.
• More Dakka: One of the strongest non-magic weapons in the game, the tommy gun, provides a +6 bonus to Combat checks, greatly increasing the number of dice rolls player can make.
• Narrative Board Game:
  • The mainline board game, Arkham Horror, has several different storylines for the players to play through, with the players choosing a specific scenario each time they play. Each scenario has a unique board layout, monster deck, and event cards that provide Flavor Text describing the strange effects of the Elder Gods on Arkham. In Third Edition, the main narrative is provided through a deck of cards known as the Codex, cards from which are put in play over the course of the game and which provide both scenario-specific events and choice points, and more "generic" cards that provide rules that can apply in multiple scenarios. They typically feature Multiple Endings as well, with a Golden Ending if the players manage to win without the Elder Gods manifesting in Arkham, endings for straight up beating the Old Ones in a boss fight, and failure states as well.
  • The card game, Arkham Horror: The Card Game, provides multiple scenarios for the players to play. Many scenarios come in several parts and are designed to be played over multiple sessions, as in a Campaign Board Game, but there are also multiple stand-alone scenarios that players can play either as part of a campaign, or as one-offs just for fun. These have large paragraphs of text in their rulebooks to relate both the stories' beginnings and Multiple Endings, as well as "plot cards" that change and evolve as the players play through the scenario. Notably, the stand-alone scenarios are often stranger and wackier than the scenarios that come as part of overarching plots.
• Nintendo Hard: Just how difficult the game is depends a lot on the Ancient One in play, the players' skill levels, and a good deal of luck. No matter what, it's generally very difficult to actually win.
  • The game itself without any expansions is not terribly difficult once you get used to it, but the expansions make the game considerably more challenging, mostly by adding an additional task that the players must work at to prevent the Ancient One from awakening prematurely. The difficulty varies by expansion; the earlier expansions were not too bad, while other ones, such as Innsmouth, make winning the game considerably more difficult, and sometimes you will lose in a manner which is almost completely unavoidable.
  • The Black Goat of the Woods expansion adds in a literal difficulty setting. Before the start of the game, players can choose from one of five possible difficulty cards labeled "Discomforting", "Nauseating", "Mind-Damaging", "Ye Liveliest Awfulness", and "Ultimate Cosmic Evil" in ascending difficulty. The easier difficulties can finally alleviate the incredible harshness of the game (Discomforting starts every unstable location with double clue tokens and puts double clue tokens down during each spawn), but the others can make the experience even worse (Ultimate Cosmic Evil starts with the Terror Level at 5, the General Store closed, 5 allies are returned to the box, and two Mythos cards are drawn and resolved per turn).
• Non-Health Damage: Each of the Ancient Ones attacks in a unique way, including removing the investigators' clue tokens, monster trophies, gate trophies, Allies, or even hands. Investigators who can't pay the price are devoured on the spot.
• Nonstandard Game Over:
  • When playing against Azathoth, if he ever awakens, it's an instant Game Over.
  • When playing against Shudde M'ell, if you ever must reveal a rubble token when all of them are already revealed, it's an immediate game over.
  • When playing with King in Yellow expansion with the Act Deck, if it ever progresses to Act 3, it is over (the Ancient One doesn't even wake up). The investigators must stall it at all costs.
  • One way for everybody to lose except one player is if they complete the task "Joining the Winning Team". When this happens, every other player dies instantly and the player who turned traitor is the only winner.
• No Saving Throw:
  • If playing against Yog-Sothoth, each time an investigator gets lost in time and space, (s)he is gone; the only investigator who can avoid this is Sister Mary, and only because her ability prevents her from being lost in time and space in the first place.
  • Quachil Uttaus will outright kill the current first player each turn, unless you somehow prevent him from attacking; unlike Atlach-Nacha, who has a similar form of attack, you can't substitute an ally in place of an investigator, or at least choose which investigator will be killed first, buying some time for the main damage dealers.
  • Zhar will first disable the first player's arm, and then kill him/her on the next turn, unless you prevent it from attacking.
  • On more general note, many "Sinister Plot" cards include things like "first player dies before he may attack. Other investigators attack as usual", or something just as cheap. Though they are parts of the "Epic Battle" set, which is completely optional.
• No-Sell:
  • Some monsters (and Ancient Ones) have Immunities (either Physical or Magical), which prevent weapons/spells with the appropriate type of damage from being used against them. There's also a weaker form of this (which only halves bonuses), called Resistances. There's also one monster (Lloigor) who has Immunity to Weapon damage, meaning you may use only spells against it (basic Physical Immunity at least does not prevent the use of Magical weapons).
  • Some allies provide defence against some negative effects:
    • Eric Colt, protects you from taking Horror from the Nightmare effect on monsters.
    • Tom "Mountain" Murphy protects you from taking damage from the Overwhelming effect on monsters.
    • John Legrasse also allows you to ignore the Endless effect on monsters (which prevents them from being taken as trophies).
  • A couple of investigators have this kind of ability, too:
    • Mark Harrigan can't be arrested or delayed, at all.
    • Sister Mary can't be lost in time in space (instead, she instantly returns to Arkham). This comes in handy when playing against Yog-Sothoth.
• Not-So-Harmless Villain: Azathoth is the Idiot Sultan, incredibly difficult to awaken and unhelpful toward those trying to wake him up. On the other hand, if he does wake up, it's The End of the World as We Know It. In the Innsmouth expansion, he becomes even more dangerous, as the rise of the Deep Ones can, in fact, wake him up. Other expansions have other mechanics to help speed up things, even if less potent.
• Obvious Rule Patch: Later versions of the rules specifically tell you to redraw if the initial draw is one of several card types likely to render the game unwinnable before it even starts if it's the first card drawn.
• Official Game Variant: The Fantasy Flight site includes semi-official house rules from the game's creator Richard Launius. In addition, there are investigator sheets for Gabe and Tycho from Penny Arcade Adventures, with Annarchy as an ally.
• Oh, Crap!: The aptly named Mythos card, "No One Can Help You Now", which prevents gates from being sealed.
• One Curse Limit: The conditions "Cursed" and "Blessed" cancel each other out and can't stack with themselves, so if a Cursed character would get another Curse, they ignore it. All Curses are the same — only rolls of 6 count as successes.
• One-Hit Kill:
  • While some Ancient Ones have some form of damage (though not all of them deal Stamina/Sanity damage directly, instead using other means to determine how long investigators can survive), Quachil Uttaus and Atlach-Nacha outright kill one investigator per attack (in the latter's case, you may use an ally as a substitute or at least choose who to sacrifice first, while the former simply kills the current first player).
  • Several monsters (mainly masks of Nyarlathothep) can devour an investigator who fails some of the skill checks against them.
  • If you're unlucky when going up against the Dunwich Horror and draw the card where it instantly kills you if you fail to beat it... well, you better hope you beat it.
• One-Hit Polykill: Some of Ancient Ones' Sinister Plots allow them to kill several investigators in one go, though specific criteria for choosing targets varies between Ancient Ones.
  • Several of the Ancient Ones such as Chaugnar Faugn or Tsathoggua have checks which require an investigator to discard or die immediately. It's possible for multiple people to fail this check in a single turn, killing a lot of your team instantly. Unlike a lot of the core Ancient Ones in the base game, these ones do not have a roll to avoid having to pay. Either pay or die.
• One Stat to Rule Them All: Averted. Fight and Lore are arguably the most important stats in the main aspects of the game: combat, spells, and gate closing. However, any stat can be called on during a random encounter, so focusing too much on your Fight/Lore can ultimately cause more harm than good.
• One-Steve Limit: Conjoined Twins Zhar/Lloigor are called by the former's name to distinguish them from the "Lloigor" enemy.
• Permadeath: Investigator can recover from being driven insane or knocked unconscious, but if they're "devoured", they're gone for good; time to start anew as another investigator. Generally, this happens either when both health and sanity drops to zero simultaneously, if max health/sanity drops to zero or if investigator gets defeated while fighting the Ancient One, but some monsters, encounters and other effects can trigger it immediately.
• Persona Non Grata: Part of what causes the "barred from the neighbourhood" effect, preventing you from entering the locations in a neighbourhood.
• Piñata Enemy: Mi-go are fairly weak and killing one gives you a unique item.
• Plot-Triggering Death: Many of the characters' backstories have this as a motivation. Examples include George Barnaby's wife, Kate Winthrop's professor, and Michael McGlen's friend.
• Pocket Protector: In Third Edition, some items have Health, allowing you to place damage on it that would otherwise be taken by your investigator.
• Point of No Continues: Normally, when an investigator is devoured, their player can choose a new one to continue playing, but this is not the case during the battle with the Ancient One; if your investigator is dead, you are eliminated from the battle.
• Power Creep: The expansions introduce bigger and badder bosses and monsters, heralds, and more ways for the Ancient One to Awaken. To compensate, stronger investigators, items, and skills are introduced.
  • In the regular game, most investigators have abilities like reducing damage, drawing extra X cards, or being able to restore Sanity and Stamina when in the same neighbourhood. Expansions introduce investigators with abilities such as being able to bypass horror checks, letting other investigators use your clue tokens, and making it much much easier to seal gates.
  • Slightly downplayed in that Cthulhu, Mandy Thompson, and the Elder Signs (one of the most powerful Ancient Ones, investigators, and items, respectively) are all part of the regular game.
• The Professor: Professors Armitage and Walters.
• Race Against the Clock: Trying to seal all the portals before the Doom track fills and the Ancient One awakens.
• Rag Tag Band Of Misfits: Very likely the players' investigative group. It's easy to have a group made up of a crooked Politician, a Federal Agent, a Street Urchin, and a Cook.
• Random Encounters: There are two types of encounters – encounters in Arkham, and encounters in Other Worlds. The Black Goat of the Woods also added the possibility of joining the cult of Shub-Niggurath and taking special encounters at the cult's sites: the Woods, Black Cave, or Unvisited Island.
• Random Event: Each turn, during Mythos phase, a Mythos card gets played, with varying effects: some one-time event, long-lasting effects, the "rumours" which gives investigators a mini-task of sort, usually with time limit, monsters spawning, etc. They also opens the gates in random places, spawns the clues in random places, forces certain enemies to move around the field, and other effects.
• Random Number God: Perhaps the real indescribable, eldritch horror in the game. Made more or less forgiving by the "blessed" (successes occur on die rolls of 4, 5, or 6) or "cursed" (successes only occur on a die roll of 6) statuses; a Cursed adventurer is generally screwed until they can shake it off or otherwise buy their way out of it at the church.
• Sand Worm:
  • Dholes are massive, powerful burrowing worms that resist both kinds of damage, will harm your Sanity and Stamina regardless of rolls, and are just hard-hitting and hard to kill to boot.
  • Chthonians are squid-like burrowing worms that are fairly powerful, but their real threat comes from causing earthquakes that automatically damage all investigators in Arkham.
  • And then there's Shudde M'ell, an Ancient One who is essentially the god of Chthonians and can cause earthquakes strong enough to entirely devastate Arkham.
• Sanity Meter: You have Sanity points in addition to Stamina. Sanity is lost casting spells, seeing monsters, or having stressful encounters; when you lose it all, you're sent to Arkham Asylum to recover.
• Screw This, I'm Outta Here: Every time the Terror level rises, someone from the ally deck is discarded, signifying people fleeing Arkham as monsters take over.
• Sealed Evil in Another World: 3rd Edition includes this as a way to defeat several Great Old Ones:
  • Azathoth is utterly impossible to fight directly, but the investigators can perform a ritual to lure it into a lifeless alternate future Earth before it can end the world.
  • One way for the Investigators to defeat Ithaqua is to perform a Banishing Ritual to relocate him to an uninhabited planet, depriving him of both cultists and victims.
• Searching for the Lost Relative: Several characters searching for lost relatives, in the midst of a town invaded by the Chaos.
  • Jenny Barnes is searching for her sister Isabelle, abducted in Paris by a cult, and will always find her. The only difference is whether she will be alive and in one piece... or several.
  • Wendy Adams wants to find her Disappeared Dad. She finds him alive if she passes her personal story.
  • Hank Samson is looking for his Pa. He successfully finds him if he passes his personal story, otherwise his fate remains unknown.
• Shotguns Are Just Better: A shotgun is one of available weapons in this game; its main gimmick is the ability to convert each 6 into two successes instead of one during an attack.
• Shout-Out:
  • Many of the Allies are characters from Lovecraft's stories.
  • Several of the encounters at Velma's Diner make mention of the coffee and the cherry pie.
• Skippable Boss: No Ancient One is mandatory to face in battle in order to win; it's perfectly possible to finish the game before the Doom track reaches the awakening threshold. In Azathoth's case, it's only way to win at all.
• Snake People: The Serpent People are borrowed from Robert E. Howard's Thurian Age, and cultists of Yig are actually disguised serpent priests.
• Solo Tabletop Game: Though the game is listed for 1-8 players, solo play is made possible since monsters generate and events happen according to the Mythos deck. Also, the Ancient One has its own character template.
• Special Attack: Each Ancient One (except for Azathoth) has 3 "Sinister Plot" cards, which are supposed to make the battle even more unfair. Each one of them may only trigger once (at random) when another "Epic Battle" card instructs so. They are only usable with "Epic Battle" cards, which are optional. Usually, they are either actual attacks or some defensive/regeneration abilities, but there's also some more exotic situations.
• Stalked by the Bell: Each Ancient One has a Doom threshold; once it's reached, the Ancient One awakens and the final battle starts. Almost all Ancient Ones are capable of annihilating an ill-prepared (or just unlucky) team, so usually it's advisable to finish the game before this happens.
• Start X to Stop X: The spell "Call Ancient One". Using this card, you can summon the Ancient One yourself so you can fight it on your terms. (If you do this with Azathoth, you have no one to blame but yourself.)
• Super-Persistent Predator: Hounds of Tindalos may pursue investigators in any location except for St. Mary's Hospital and Arkham Asylum.
• Support Party Member: Several investigators have abilities that help other investigators (such as by healing them, allowing to redo failed skill checks, etc). Often, such investigators have subpar basic stats, and require protection from their teammates.
• Taken for Granite: The petrifying solution is a chemical from The King In Yellow that serves as a powerful one-shot weapon with a hefty combat bonus and ignoring the physical resistance and Endless abilities. Amusingly, in the original story it was lifted from, the effect is only temporary.
  • The fate of any unfortunate victim who have seen the gaze of Ghatanothoa is to forever become a half-petrified mummy. All of this while being perfectly alive and aware.
• Team Killer: If you pick up "Joining the Winning Team" and start actively working to complete it, don't be surprised that the rest of the table doesn't help you given that you completing said objective and winning the game means they all lose.
• Time Bomb: A common item that can detonate 1-3 turns after being placed, killing all monsters and investigators on that location.
• Timed Mission:
  • Almost all Personal Stories are timed, either by the Doom track, or by the Terror level. To make things worse, some of them depend on something outside of the investigator's control.
  • Any play against Azathoth is this, since unlike other Ancient Ones, his awakening is an instant game over.
• Time-Limit Boss:
  • Most Ancient Ones limit the time you have to defeat them in battle, either by an explicit time limit, or by gradually consuming your limited resources and killing you once their supply dries up.
  • While playing with Epic Battle cards, there's always "The End of Everything" card, which instantly ends the battle in failure. The earliest this may happen (barring some specific circumstances) is on the ninth turn.
  • Amongst non-Ancient Ones, this also applies to Tendril of Nyogtha (only used when played against Nyogtha as the Ancient One); you have exactly 3 turns to defeat it, you can't run from it, and if you fail, you get Devoured.
• Tomato in the Mirror:
  • Drawing an Innsmouth Look card and discovering you are a Deep One hybrid.
  • If two gates to R'lyeh are open at the same time, Amanda Sharpe discovers the truth behind those dreams she's been having...
• Tome of Eldritch Lore: You can find famous Mythos books like the Necronomicon in this game. Reading them gives you a chance to learn spells or skills, at the cost of insanity.
• Town with a Dark Secret: Dunwich and especially Innsmouth. The difference being that in Dunwich, everyone is afraid of its secret, and in Innsmouth, everyone is part of it.
• Turn Undead: The Cross is a magical weapon that only provides a combat bonus against undead enemies. It does, however, always provide a bonus to a horror check. Jim Culver, meanwhile, has a special ability that lets him spend a clue token to auto-defeat any undead foe.
• The Undead: One of the possible traits which monsters can have. They are vulnerable to the Cross (in fact, it only works on them).
• Vertical Kidnapping: Nightgaunts will swoop in from above, overpower you, and drop you in the nearest portal. This can be beneficial; they will do this in Other World locations and return you to Arkham, allowing you to then close the portal.
• Wound That Will Not Heal: The Dunwich Horror expansion introduced an injury/madness mechanic. When an investigator gets knocked unconscious, they may choose, instead of discarding clues and items, to take an Injury card. This allows the investigator to save all their belongings and will restore their Stamina to the maximum (instead of leaving with just 1 point). Each Injury is unique and provides different permanent penalties for its wielder. Unlike normal damage, Injuries are much harder to get rid of, and if an investigator manages to collect two similar Injuries, they will be instantly devoured. Madnesses work in a similar manner for Sanity losses, but usually have more exotic effects. For example, Claustrophobia damages the Sanity of investigators who start their turn in any named location (but not on streets or in the Other World), while Violent Outbursts forbids them from taking evasion attempts against monsters.
• Zonk: While most of the cards in the Exhibit Encounter deck from the Revised Curse of the Dark Pharaoh provide an opportunity to gain an Exhibit Item, one of them can result in the top card of the Exhibit Item deck being removed from play automatically.

Tropes specific to Leagues

Arkham Leagues

First Arkham League

• Arbitrary Equipment Restriction: All scenarios have certain cards forbidden from being used, with final scenario outright removing entire deck of Unique Items (as well as Exhibit Items, as scenario uses The Curse of Dark Pharaoh expansion). There's no explanation in-story, it's done solely to increase difficulty.
• Cast from Hit Points:
  • In "It's Good to be the King", several Unique Items (listed in scenario reference sheet) requires sacrificing 2 Sanity in order to be used; all of them are associated with Hastur in one way or another.
  • In "Knocking on the Gates", investigators can at any point sacrifice 2 Sanity to gain 2 Clues; there's no limit, for as long as they have enough to pay the price.
• Continuing is Painful: In "Knocking on the Gates", whenever investigator gets driven insane, a Blight enters play for the rest of the game, making it significantly harder for everyone.
• Danger with a Deadline: In "Feeding the Hand that Bites", at the end of Upkeep phase, each investigator who doesn't have full Stamina, loses Stamina equal to current Doom — unless they're in the Arkham hospital or lost in time and space. This effect turns off in the Last Battle.
• Dice Roll Death: In "Feeding Time", investigators who ends their movement in the Black Cave must pass a Fight check, or they would die. The modifiers scales with Doom, so it goes from relatively easy to borderline impossible as the game goes on.
• Early Instalment Weirdness: First Arkham League is the only one to lack either campaign-wide storyline or campaign-wide mechanics; all other Leagues would have some.
• Fed to the Beast: "Feeding Time" involves Tsathoggua slumbering in the Black Cave, and has several mechanics built around him eating whoever ends up in the cave:
  • The monsters are moving every turn towards the Black Cave, where they would be fed to Tsathoggua unless killed on the same turn when they got there, increasing either Doom or Terror level.
  • Investigator who ends in the Black Cave, must pass a Fight check or be instantly devoured (literally); the modifier stacks with Doom, and can very quickly make the check unsurvivable.
• Friend or Foe?: "Masquerade Ball" has its mechanics built around inability to tell friends from foes, as cultists of Nyarlathotep are everywhere:
  • Investigators have to pass a Will check to trade items; on a failure, trade is cancelled for that turn.
  • When investigator gains an Ally, they must pass hard Will check or discard that Ally and run on the street in horror, like from a monster.
• Go Mad from the Revelation: In "Knocking on the Gates", for every 2 Spells, Tomes and/or Unique Items, investigator loses 1 Sanity at the end of every Upkeep phase. It's likely related to the Ancient One being Yog-Sothoth, who's associated with forbidden knowledge, which unprepared minds often can't handle.
• Luck-Based Mission: "Tide of Serpents" has a mechanic when having two or more Cultists in the same location at once instantly awakens Yig, potentially way before investigators are ready to face him. The problem is, whenever monsters spawns, which ones would appear is decided by random draw.
• Masquerade Ball: The setting of the namesake scenario: it's a masquerade ball in Arkham, and thus, it's easy for Nyarlathotep's cultists to sneak in, which adds to the investigators' paranoia, by making them unable to trust each other or potential Allies (which is represented in the actual mechanics), and making them lose Sanity whenever new Cultists, Maniacs or Nyarlathotep's Masks sneaks in.
• Maximum HP Reduction: In "Brood Fresh", in addition to their standard effects, Eihort's brood tokens also decreases maximum Stamina or Sanity of affected investigator by 1.
• Mind Rape: In "Miscreants and Miscreation", whenever investigators defeats a Child of Abhoth, Abhoth himself speaks in their mind, forcing them to pass a Will check or lose 2 Sanity.
• No Item Use for You: All scenarios removes certain items, spells, skills or allies, but the final one, "All Things Must End", removes entire decks of Unique and Exhibit Items.
• Random Event: "The Sleeper Awakens" doubles amount of Mythos cards played each turn; only the first card drawn opens the Gates, though.
• Sadistic Choice:
  • In "It's Good to be the King", several locations gains additional rule: if the clues spawns there for any reason, there also spawns a Yellow Sign token; if investigator gathers those clues, they also gains the Yellow Sign, and have to either put into play a Blight card and suffer from its permanent debuffs, or put that Yellow Sign on the Doom track.
  • In "Feeding the Hand that Bites", leaving the Cultists alive can very quickly lead to Y'Golonak awakening, but actually taking them down increases Terror level.
• Timed Mission: "All Things Must End" has Azathoth as the Ancient One (which counts by itself, given his mechanics), and ups the difficulty by having Ghroth as the Herald (whose abilities were amplified).
• Took a Level in Badass:
  • In "Feeding Time", the Formless Spawns becomes much faster (moving by three steps instead of one), and having harder Horror check modifier.
  • In "It's Good to be the King" (which is all about Hastur), all "yellow" (stationary) monsters gains Horror rating of (-4), which is very high. The same applies to all monsters appearing in "yellow" locations (both Arkham location and Other Worlds).
  • In "Feeding the Hand that Bites", Y'Golonak's ability to gain Doom whenever Tome is revealed is much more dangerous, as whenever Cultist moves for any reason, the top 3 cards of the Unique Items deck gets revealed, and Doom increases for any Tome shown that way (the card then gets put on the bottom of the deck, in any order). And whenever monster surge occurs, the first monster drawn is always Cultist in this scenario.
  • In "Feeding the Hand that Bites", all monsters have their Stamina damage increased by 2.
  • In "The Sleeper Awakens", Cthulhu gains bonuses to his Combat rating for each undefeated Chthonian or Star Spawn left on board... and even larger for each monster trophy of those enemies still in investigators' possession.
  • In "All Things Must End", Ghroth (who's used as the Herald) has his abilities amplified. Now, the players have to throw a dice whenever a Gate opens (excluding monster surges), and have to throw two dices if the Mystic-type environment card enters play. The price of cancelling the throw is also higher: 2 Clues if it's triggered by Gate, and 3 if it's triggered by Mystic card.
• Zerg Rush: In "Miscreants and Miscreation", whenever monsters must spawn, instead, twice as many would appear.

Second Arkham League

• Anti-Frustration Features: In the fourth scenario, all Clues preserved from the previous scenario spawns in the Woods at the start of the game. In this particular scenario, if a Gate opens there, it would not discard those clues. The Clues which should spawn in this location while it has a Gate there, would go directly into a bank instead of being discarded.
• Big Bad Ensemble: Couple of scenarios have two Ancient Ones at once. Scenarios have special rules in regards to which Ancient One gains Doom and when, and allows them to both awake at the same time. If one awakes and gets eliminated, they would cease to affect gameplay.
  • After altering between Shub-Niggurath and Ithaqua for four scenarios, the League puts them both at once in the fifth scenario, representing their respective cults fighting each other and trying to summon their patron deity.
  • The eight scenario has Shudde M'ell and Glaaki.
• The Corruption: The third scenario is entirely build around Cult of the Black Goat, with all the corruption it involves. Preserving the Clues in the bank gets investigators tons of Corruption cards before the game even starts, accumulating too much Corruption or too many Clues gets them instant membership in the Cult (with risks of gaining even more), and attempts to evade Cultists instantly "rewards" with a Corruption card. As the number of Corruption cards is finite, and if the deck runs out, it means instant awakening of Shub-Niggurath, it's a major threat.
• Cult:
  • First five scenarios is all about investigating activities of two cults, Cult of the Thousand Young (aligned with Shub-Niggurath) and Silver Twilight Lodge (which tries to summon Ithaqua); the League alters between them until finally puts both together in the fifth scenario.
  • Seventh scenario brings the new cult, which worships Glaaki, and doesn't care that their patron deity wants to destroy the world.
• Do Well, But Not Perfect: In penultimate scenario, if investigator accumulates more than two Gate Trophies, they must discard them and get 2 Spells instead. Losing Gate Trophies in such way may be detrimental to both winning the game by closing the gates, and to surviving Last Battle if Yog-Sothoth awakens anyway.
• Drowning My Sorrows: Michael McGlenn became heavy drinker after losing his best friend Louie.
• First Person Narration: Unlike First League, there's a League-wide plot, mostly narrated by Calvin Wright.
• Gameplay and Story Integration:
  • In the fourth scenario, the members of the Silver Twilight Lodge are in the middle of undergoing interrogation by police, so the Lodge is closed for duration of scenario. As with any closed location, it can still be visited for the purpose of dealing with Gates.
  • After fifth scenario, acknowledging that Cult of the Thousand Young and Silver Twilight Lodge were defeated and forced to run from Arkham, their associated locations (the Woods and Silver Twilight Lodge) gets locked from the start in all subsequent scenarios, excluding two final ones.
  • The backstory for seventh scenario acknowledges Michael's extreme toughness, by pointing that he recovers from any injuries surprisingly quickly; in gameplay, Michael's signature ability is reducing incoming Stamina damage by 1.
• Healing Factor: In penultimate scenario, all Lore checks gets harder (requiring one more success to pass), but any time investigator passes them, they restores 1 Sanity.
• Heroic Sacrifice:
  • In the seventh scenario, any investigator may let themselves be devoured in order to decrease the current Doom by 3.
  • In the penultimate scenario, any investigator may sacrifice themselves (being devoured in process) in order to remove the Dunwich Horror from the board (it starts in play immediately). It only works once, after that, the Dunwich Horror resumes working as normally.
• Instant-Win Condition:
  • In the first scenario, investigators wins if they either close the number of Gates equal to number of players, plus four,^note  Scenario tracks total amount of closed gates, not amount of trophies regardless of how many are still left. Beating Shub-Niggurath in the Last Battle would also work. All other methods are disabled, and the players aren't allowed to seal the gates.
  • In the second scenario, closing the number of gates equal to number of players, plus four (same as in the first one) wins the game instantly. The players may also win by sealing 6 Gates or beating Ithaqua in battle
• Luck-Based Mission: In the fourth scenario, Ithaqua instantly awakens if there's ever two or more Cultists on the streets at once. Unfortunately, they may easily end up there completely at random. Makes any lone Cultist a high-priority target.
• Maximum HP Reduction: In the final scenario, whenever investigator gets devoured, the other investigators loses 1 point of maximum Stamina or Sanity. Additionally, whenever investigator closes or seals a gate to R'lyeh, they loses 2 points of maximum Stamina and Sanity. All of this is on top of playing against Cthulhu, who already decreases both stats by 1 since the start of the game. Calvin Wright is immune to all those effects.
• The Mole: Investigators are forced to join the Cult of Thousand Young in third and fourth scenarios, in attempt to find out more about their activities.
• Sand Worm: In the sixth scenario, all Cultists counts as Chthonians (giant worms dwelling underground), which, given how many Cultists in the pool, greatly amplifies their numbers.
• Power at a Price: In the third scenario, for every 3 Clues investigators wishes to preserve in the bank, each investigator must take a Corruption card. Considering penalties those cards incur, the fact that there are even more ways to gain Corruption later, and that Shub-Niggurath would awake if the deck runs out, that power is indeed risky.
• Required Party Member:
  • In all scenarios excluding the final one, Calvin Wright is presented as an Ally. At the start of the scenario, one of the players must take his card, at the cost of discarding one Unique Item.
  • In the final scenario, Calvin Wright is presented as one of the playable investigators; one of the players must play as him.
• The Scapegoat: In the third scenario's backstory, Michal McGlenn gets arrested in the Woods, when walking around with a Tommy Gun; the police wants to scapegoat him for all the disappearances, not really bothering with finding any proof; then several more people disappeared, and they were forced to listen to him. He's still playable in the third scenario, despite only being released by the start of fourth.
• Second Episode Introduction: Some (but not all) playable investigators actually appears as characters in-story. The first scenario only introduces Jenny Barnes, Michael McGlenn, Joe Diamond, Ashcan Pete and Dexter Drake. Sister Mary, Vincent Li, Harvey Walters and Amanda Sharp, despite being playable in the first scenario, only gets formally introduced in the second. Besides them, Jim Culver would be briefly mentioned in the seventh (despite not being playable there, and originally introduced in the third scenario), and intro for the final scenario mentions by name Marie and Bob.
• Timed Mission: The sixth scenario has Shudde M'ell as the Ancient One, and speeds up his city-destroying mechanic by making all Gates openings in the Science Building and the Witch House count as monster surges (thus, provoking locations being destroyed), and Dunwich Horror, instead of increasing Doom, causes random locations to be destroyed (as it used Mythos cards to determine location, it would destroy unstable locations instead).
• Too Awesome to Use: The Clues are much harder to obtain, as no investigators starts with them, and most scenarios disables them spawning at the start of the game. What's worse, all spent Clues are gone for good, and not just for duration of scenario, but for duration of the entire League; the more Clues you spent in scenario 1, the less Clues you would have in scenario 2, and so on. And some scenarios forces investigators to pay for preserving those Clues (like third scenario forcing investigators to take Corruption cards for every 3 Clue), or disables certain ways to gain them (like second scenario disabling clue spawning by Mythos cards or by defeating certain enemies, but makes it possible to get them by taking monsters as trophies).
• Took a Level in Badass:
  • In the first scenario, all enemies have Horror rating of (-3), and Sanity damage of 2, which, for most of them, is a major upgrade. It's on top of buffs they receives from Ancient One being Shub-Niggurath.
  • In the fourth scenario, Ithaqua's signature ability, instead of merely causing Stamina damage, decreases maximum Stamina by 1.
  • In the fifth scenario, Ithaqua gains Combat rating of (-6) and Physical Immunity, to make him equal with Shub-Niggurath.
  • In the fifth scenario, Cultists are affected by both Ancient Ones' bonuses, giving them 4 toughness.
  • In the seventh scenario, Cultists receives massive boost to their stats, gaining Combat and Horror ratings of (-3), 3 Stamina damage and 2 Horror damage. It's on top of them already being stalking monsters due to Ancient One being Glaaki. And if two or more gathers in one location, they would increase Terror level by 1 on every Mythos phase.
• You Are Already Dead: In the seventh scenario, if investigator gets knocked unconscious by Cultist, that Cultist's token gets put on that investigator's sheet. If Glaaki awakes, all investigators with Cultist tokens on their sheet gets devourted before the battle even starts.

Spanish Leagues

First Spanish League

• Arbitrary Equipment Restriction:
  • In "The Legend of the Scarab", investigator who carries Walter Gilman as an Ally, can't have more than 1 Monster Trophy; no explanation is provided why.
  • In "Welcome, Mr. Whateley", investigator who carries Walter Gilman as an Ally can't gain Clues; no explanation is provided why.
• Arbitrary Mission Restriction:
  • "The Dreams in the Witch House" puts several restrictions on players; some are explained (like Keziah's curse making the Gates in her house and on Unvisited Isle impossible to seal), others (like "you can only seal the Gate if you spend 5 Clues and a Tome) occurs jut because.
  • "The Strange Seduction" disables sealing the Gate on Unvisited Isle. There's on in-story explanation for it other than to make it even easier to spawn Cultists there.
  • "The Three Armies of the King" makes the Riots also block access to locations connected to their current street (even through encounters); there's no mention of it in story, and it's not clear why it's even in place, as investigators have to defeat them anyway in order to win the game.
  • In "The End of the Beginnings", investigators can only win by sealing 6 Gates; it's clearly done just to make Azathoth more dangerous, given his infamous reputation as the "weakest" Ancient One.
• Brainwashed and Crazy: In "The Three Armies of the King", Walter Gilman does, actually, read the "King in Yellow", with predictable results for his already unstable sanity. Now, investigators have to capture him and un-brainwash him before it's too late.
• Brown Note: In "Gilman and his King", whenever investigator draws a card containing Yellow Sign on the image, or the words "Yellow Sign", they lose 1 Sanity. If they draw the "King in Yellow" Tome, all investigators loses 1 Max Sanity. This effect applies even to starting equipment.
• Choose a Handicap:
  • In "The Pharaoh's Awakening", the players must divide several pairs of Boon+Curse and Bane+Bless.
  • In "Goodbye, Mr. Whateley", the players starts with either Madness or Injury card. The player who takes Walter Gilman, always starts with a Madness.
• Co-Dragons: In "The End of the Beginnings", investigators have to deal not only with Azathoth, but also with Nyarlathothep and Yog-Sothoth, with latter two only serving to make dealing with Azathoth harder. They can't use their powers, unless at least one Gate is opened to Dream Land or Yuggoth, respectively. They also don't gain Doom, instead, they awakes if two of "their" Gates gets opened at once, with reduced Doom (they take it entirely from Azathoth's sheet); once defeated, they leave play permanently.
• Contractual Boss Immunity: In "The Beginning of the End", Walter Gilman is immune to any and all effects which would defeat, discard or move him, and can't be attacked by the players; his token is only used to mark his movement.
• Cool Gate: "The Dreams in the Witch House" is mainly build around increasing the danger that Gates possess. Not only scenario has Yog-Sothoth as the Ancient One (which ups the difficulty of closing the gates), it also increases the cost of sealing the Gates by forcing investigators to discard a Tome as well, and make the Gates on Unvisited Island and in Witch House both harder to close and unsealable.
• Curse:
  • "The Dreams in the Witch House", if the Gates opens in the Witch House or on the island, it's not possible to seal them, and investigators receives penalties when trying to close them. It's attributed to Keziah Maison's curse.
  • In "The Pharaoh's Awakening", investigator who has Walter Gilman as an Ally, can't discard Curse, but doesn't lose Stamina from herald's effects.
• Dead All Along: The final scenario reveals that real Walter Gilman has died a year ago; someone or something has passed themselves for him.
• Developer's Foresight: In "The End of the Beginnings", if Azathoth has so much Doom that awakening Nyarlathotep would exceed his normal Doom track of 11, Nyrlathothep wouldn't awake; instead, his abilities would become permanent.
• Disc-One Final Boss: Walter Gilman (or whoever passed themselves for him) gets dealt with in penultimate scenario. The one after that deals with the fallout of chaos which Walter started.
• Face–Heel Turn: Walter Gilman turns evil in the penultimate scenario, and has to be stopped.
• Gameplay and Story Integration:
  • As "The Dreams in the Witch House" is all about investigating the Witch House, all investigators starts there instead of their usual starting locations.
  • As "Welcome, Mr. Whateley" is mainly set in Dunwich, the following scenario, "Goodbye, Mr. Whateley", which starts right where the previous ended, has all investigators starts in Dunwich locations of their choice instead of Arkham.
• Increasingly Lethal Enemy: In "The Beginning of the End", Walter Gilman moves by one street more for every two Allies he has — and he's already a Fast monster (moves twice).
• Instant-Win Condition: In "The Dreams in the Witch House", investigators wins if they either seal 6 Gates, or close the number of Gates equal to number of players, plus four (regardless of other factors).
• Killed Offscreen: Walter Gilman gets killed by unknown being between 9th and 10th scenarios; investigators only finds his corpse.
• Luck-Based Mission:
  • "Welcome, Mr. Whateley" has investigators blindly searching or Walter Gilman in Dunwich. His exact location is randomised, and one of the tokens marking his possible location reshuffles the tokens, including already discarded ones. It's made worse by the fact that investigators must succeed before Abhoth awakens.
  • In "The Beginning of the End", progress of Gilman's ritual depends several factors which are fully or partially outside of the players' control:
    • He only gains Allies on Terror level increase. Terror level by itself is hard to manage, due to many random factors affecting it.
    • He has to pass the street connected to location with opened Gate to R'lyeh (it may or may not be closed already, or open in Dunwich, where he can't go at all), while having all other sacrifices done and at least one Ally to spare.
    • Even when Walter Gilman tries to do the final sacrifice, the first player throw a dice certain amount of times, which depends on Terror level (the lower it is, the less dices gets thrown); if at least one gives 5-6 result, it's game over, otherwise, Gilman goes on another circle.
• Nonstandard Game Over:
  • In "The Dreams in the Witch House", discarding Walter Gilman for any reason causes immediate game over.
  • In "Welcome, Mr. Whateley", if Abhoth awakes before Walter Gilman gets found in Dunwich, the game ends in a failure immediately.
  • In "The Three Armies of the King", failing to recover Walter Gilman before Hastur awakes ends the game in a failure. Same happens if his owner gets eliminated, as investigators can't win without him, and he can't be recovered once lost.
  • In "The Beginning of the End", investigators must care about Walter Gilman working on ritual which would destroy Earth if successful. Allowing him to complete all four sacrifices means instant game over.
  • In "The End of the Beginnings", while defeating Nyarlathotep or Yog-Sothoth if they awakes wouldn't win the game, losing to them in battle still cause investigators to lose.
• No Saving Throw: In "The Strange Seduction", if Yig awakes, investigator who has Walter Gilman as an Ally gets devoured immediately.
• Required Party Member: Most scenarios have Walter Gilman as mandatory Ally for one of investigators; in order to take him, they must discard 1 Unique or 2 Common Items from their starting possessions. He always boosts Lore and Focus, but comes with penalties for whoever takes him.
• Obvious Rule Patch:
  • The sole reason why Father Ivanitsky is removed from the pool of Allies in "The Pharaoh's Awakening" is because on setup, one investigator gains a Curse, while that Ally makes investigator immune to Curses.
  • "The Beginning of the End" instructs to use 16 Allies (all Allies from the core, plus all from Dunwich), as its core mechanics are dependant on Allies, and having too many Allies leaving may otherwise break its Nonstandard Game Over.
• Power at a Price: "Goodbye, Mr. Whateley" preserves the Clues which were in investigators' possession by the end of the previous scenario, putting them on Whateley Farm (if too few were gathered, there would be 12 Clues). But to take them from there, investigators must pass Lore check, with number of successes determining amount of Clues they can take; succeeding more than twice per check would advance the track of Dunwich Horror, something investigators don't want to do too early, if at all.
• Sanity Slippage: Walter Gilman becomes progressively more unstable with each scenario, until he finally goes insane in penultimate one and tries to make entire world into a sacrifice to Cthulhu.
• Spared By Adaptation: Unlike namesake short story, here, Walter Gilman survives the events of "The Dreams in the Witch House" scenario, and continues his (mis)adventures after that. However, in the last scenario's intro, Walter's brother shows up and reveals that Walter has died a year ago, and whoever that man was, it wasn't Walter.
• Stalked by the Bell:
  • In "The Strange Seduction", investigators faces Yig, and have even less time than usually, due to all the new mechanics introduced to speed up Yig's awakening — as well as potentially making him more dangerous.
  • In "The Legend of the Scarab", investigators faces Shub-Niggurath, who, to make her possible awakening more probable, gains a new mechanic: whenever stationary monster spawns, two Doom tokens gets placed on them until they gets defeated; if the game ever runs out of of Doom tokens, the next time one would be placed, Shub-Niggurath would awake immediately.
• Timed Mission:
  • In "Welcome, Mr. Whateley", investigators must find Walter Gilman before Abhoth awakes, or they would lose. They can't even start working on their goal until he gets found, as there's only two winning conditions: sealing 6 Gates, or beating Abhoth in battle.
  • In "The Three Armies of the King", Walter Gilman must be retrieved before Hastur awakes, or investigators would lose. The problem is that he moves around the field as Fast monster (who has to be defeated before he rejoins investigators), and is invulnerable until all three Riots gets put down.
  • In "The Beginning of the End", investigators must prevent Walter Gilman from fulfilling his ritual and destroying Earth. For that, he gathers Allies through Terror level increase, and visits the streets connected to locations stated in the card "Joining the Winning Team" (which is not available for players in this scenario). Whenever he reaches required locations, he makes a sacrifice of one of his Allies. The last step is, rather than being lost in time and space, is to pass through a street connected to a Gate to R'lyeh while having an Ally to sacrifice. Investigators can't kill Walter by any means (but can slow him down by depriving him of his Allies), and must fulfil their usual mission before Walter does.
  • "The End of the Beginnings" disables all standard winning conditions other than sealing 6 Gates. And the Ancient One in this scenario is Azathoth, who would destroy the world if investigators wouldn't put those seals on by any means necessary.
• Took a Level in Badass:
  • In "The Dreams in the Witch House", Hounds of Tindalos moves every turn, making them even more dangerous.
  • In "The Strange Seduction", aside from usual effects associated with playing against Yig, Cultists gains several more bonuses which makes them more dangerous (and indirectly making Yig more dangerous):
    • They gains Horror rating of (+0) and Sanity damage of 1. Additionally, they're Endless now, meaning that they can't be taken as trophies; but instead of just being discarded, they goes on the Unvisited Island, where another Cultist joins them. They can't be sent to Outskirts either, going to Unvisited Island instead.
    • Whenever Cultist ends up on the Unvisited Island, Doom increases by 1. It stacks with Yig's usual rules of increasing Doom on defeating a Cultist. And if Cultist goes there due to being defeated, but not claimed as a trophy, it results in whopping 3 Doom tokens being added to Yig's sheet — out of 10 required to awake him.
    • If the pool runs out of Cultists (there are 6 of them in core game), Yig awakes immediately — and when he awakes, if there are more than three Cultists on the board, he improves his Combat rating by 1 for each excessive Cultist, up to (-6), same as Cthulhu.

Second Spanish League

• Anti-Frustration Features: Investigators who gets devoured during Last Battle, can still return in subsequent scenarios.
• Arbitrary Mission Restriction: Some rules exists solely for the sake of having rules, to make scenarios feel different.
  • In "Walter Gilman's Choice", when investigator returns from the Other World, they must defeat all monsters before they can close the Gate. If they evade even one, they can close it, but not seal.
  • In "The Thing in the Moonlight", monsters with Moon symbol can't be taken as trophies; they moves to Outskirts instead. No explanation given, so it's likely for the sake of symbolism.
  • In "The Tomb-Legions" makes its best to keep the players busy at the Graveyard. Whenever clues should spawn in Arkham location other than Graveyard, it spawns on Graveyard instead; if it must spawn on Graveyard, instead, a monster spawns. Additionally, the Gates there can't be sealed.
  • In "Six Shots", there are several mechanics put in place to discourage stockpiling monster trophies.
    • Investigators must roll one more success to take a monster as trophy, or they would run to the Outskirts.
    • When Eihort awakes, for each monster trophy, investigator gains additional Brood tokens (one token per trophy). But investigators may skip the Movement phase to spend Clues in order to discard their trophies.
  • "The Cave" disables clue spawning in the Black Cave, and makes investigators unable to seal any gates there.
  • Scenarios "Six Shots" and "The Cave" have the number of seals required to win the game increased from 6 to 8, for no apparent reason (however, in the latter, it drops back to 6 if all Hexagon-symbol monsters are eliminated, including from Outskirts).
  • "In the Arms of Opium" forces investigators to get delayed whenever they lose Stamina or Sanity while in the Other World for any reason.
  • In "Twilight in Arkham", when Cthulhu awakes, all investigators in Other Worlds gets devoured; it's done because of Cthulhu's unique mechanics in this scenario. Additionally, it disables victory by sealing gates.
• Back from the Dead:
  • In "Walter Gilman's Choice", failing a Combat check results in investigator's Monster Trophies coming back to life and running away; and yes, they do count towards monster level limit.
  • In "From the Dark", monsters don't get taken as trophies when defeated, at least not right away. Instead, investigator gains Clues equal to their toughness, and gets put facedown. Then, any investigator who ends their movement in location with facedown monster, can pay the number of Clues equal to monster's toughness to take them as trophy. Any unclaimed monster resurrects in the Mythos phase.
• Bag of Spilling: Zigzagged Trope; if the player keeps their investigator between scenarios, they preserve their possessions. If not, they lose them and must start from scratch the next time they pick them.
• Curse: In "The Tree on the Hill", the titular tree clearly has some evil behind it, which spreads the nightmares around Arkham (represented by Mythos cards playing on each Terror level increase), and whispers in the grass, which can actually put a Curse on investigators on monster surges (and kill anyone who's already Cursed).
• Death Is a Slap on the Wrist: Averted; unlike the base game:
  • This time around, any Common and Unique Items lost due to investigator being knocked unconscious, driven insane or devoured, gets lost permanently, and not just for duration of scenario, but for entire League.
  • If investigator gets devoured, they perish for entire duration of the League.
• First Person Narration: All scenarios' intros are narrated from the PoV of nameless narrator (who, apparently, knew Walter Gilman back when he was still alive).
• Formula-Breaking Episode:
  • "Koth of Hyboria" starts with investigators being trapped in some sort of dream world (but not Dream Lands), with many standard mechanics (Gates, Doom, Terror level, Mythos, monster movement, etc) ceasing to work till at least one investigator make it out of there and then the "normal" play starts. Once at least one investigator returns, the game resumes at usual pace, but the other investigators still must escape; the two worlds can't affect each other in any way, and monsters in dream world don't count towards monster limit.
  • "Twilight in Arkham" gets away with investigators standing still and fighting static Ancient One. This time, Cthulhu actually moves around Arkham, and investigators have to pursue him in order to fight him. Entire scenario sheet is dedicated to describing how it works.
• The Mole: In "The Cave", one investigator must get the membership in the Cult of Thousand Young; they keep it in subsequent scenarios under standard League's rules.
• Nonstandard Game Over: In "Twilight in Arkham", allowing Cthulhu to destroy all unstable locations leads to game over, unless investigators manages to defeat him in one round of battle (as the actual battle happens before the game checks for that condition).
• Permadeath: This time, investigator's death persists between scenarios, so if someone was devoured, they wouldn't return. It's possible to run out of investigators, in that case, the League ends and players lose.
• Time-Limit Boss: In "Twilight in Arkham", Cthulhu must be defeated before he destroys all unstable locations in Arkham.

Third Spanish League

• Arbitrary Mission Restriction: The main focus of the League is new "The Unknown" Ancient One, which appears in all but three scenarios (scenarios 7-9 have Eihort, Azathoth and Shub-Niggurath, respectively), and uses its own unique mechanics. There's no story, and most scenarios have seemingly random and arbitrary rules which goes unexplained whatsoever.
  • The first scenario forces investigators to pass Luck check on closing or sealing the Gate, or losing 1 Stamina and 1 Sanity.
  • The second scenario forces first player to take Madness cards whenever monster surge occurs.
  • The third scenario forces investigators to discard Clues on monster surges, or draw additional Mythos card.
  • The fifth scenario forbids investigators from taking Gates as trophies unless they pay 1 Clue.
  • The seventh scenario makes it that each time the Outskirts gets filled with monsters, Terror level rises by 2 and two monsters moves to Innsmouth Factory District. It's not explained in any way, and has little to do with Eihort (it's one of the three scenarios with fixed Ancient One).
• Ax-Crazy: In the fourth scenario, if investigator loses more 2 or more Sanity at once, they get a Yellow Sign; three Yellow Signs, and they goes irreversibly insane, joining the violent psychos razing Arkham. It's possible to get rid of one Yellow Sign during Upkeep phase, but only at the cost of gaining Madness card.
• Curse: The sixth scenario gives every investigator a special Curse of Sorrow card, which enforces certain effects on them, unless they fulfil specific task to remove the card. Lifting the curse is mandatory in order to win the game.
• Deal with the Devil:
  • The eight scenario forces investigators to make one Dark Pact each time a location gets closed due to Terror level rising. Any investigator can also take any Dark Pact they don't have yet at any moment. But each turn, at Upkeep phase, first player must throw a dice as many times as there's a number of active Dark Pacts; if any dice gives a failure, it's an immediately Reckoning; this can spiral out of control very quickly.
  • The ninth scenario forbids investigators from sealing the Gates unless they have at least one Dark Pact on their hands. Unfortunately, when Shub-Niggurath awakes, she gains all unspent Power tokens as Doom tokens, which makes making those Pacts even more risky.
• Holy Is Not Safe: In the last scenario, whenever investigator seals a Gate, everyone gets Blessed. But whenever someone gets Blessed, they gets a Madness card — which, in turn, advances Deeps Ones Rising meter (the same effect goes from gaining an Injury card).
• Unwinnable by Design: In the sixth scenario, winning is impossible unless investigators have sealed at least one Gate and all of them have dealt with their Curse of Sorrow cards (unique to this scenario).

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