Up until, say, the early 1990s, if you grew up in the United States, Canada, (maybe) Britain, and (possibly) Australia, you grew up with the popular board games, like Monopoly, Clue (or Cluedo), Scrabble, Stratego, Risk, Life, and so on. Indeed, the board game producers Parker Brothers and Milton Bradley seemed to monopolize (pun intended) our childhood board game culture. Interestingly, though, there was a surprising lack of cooperative strategic games. Sure, games like Pictionary and Taboo were cooperative party games, but there was little strategy involved, per se (note: I'm not going to argue about the tactics of Taboo, which involve knowing your teammates so that you can provide the best clues).
Pandemic was not the first cooperative strategy game; to my knowledge, Shadows over Camelot pre-dated it by three years, and dungeon crawl games existed long before that. Yet, Pandemic was certainly the most impactful in the golden age of Eurogames. Released in 2008, Pandemic is a 2-5 player game (though you could play 2-5 roles by yourself) in which each player assumes a role that grants them a unique ability. During each turn, the active player can perform up to four actions, such as moving from one city to another, or performing one or more special actions, such as removing one disease cube from an infected city per action. However, each role has abilities that bend these rules; for instance, the ever-useful Medic role can remove all of one type of disease cubes in a city with only one action.
After the four actions are completed, the player draws two cards. Then, the player draws three City cards; the first City card drawn requires the players to put three disease cubes on the indicated city; the second City gets two cubes; and the third city gets one cube. Each city were infected with a specific disease cube depending on the region (e.g. Asia generally gets the red disease cubes). In this way, each player plays his turn, and then plays as the game's artificial intelligence (AI), so to speak. I would guess that playing as the game AI was not a novel concept, but that combined with cooperative play created a feeling that everyone was somehow creating their own problems despite themselves.
Gameplay ends when all four diseases are "cured," which results in victory for the players. If the players fail to do that before all of one particular disease's cubes (25 of them) have been deployed, the draw pile is completed depleted, or before there have been eight Outbreaks (when a city exceeds three of one disease's [color] cubes, which cases excess cubes to spread to neighboring cities), they lose. Everyone loses -- not one player... Everyone. Of course, I'm excluding several details because I want to avoid a rules explanation; the basic idea is that you win as a team, and you lose as a team, which was not a common concept, especially among the Parker Brothers and Milton Bradley games.
With an accessible theme, a one-hour play time, a low price point of around $30 USD in 2008, and a smaller box than a lot of the connoisseur games out at the time, Pandemic ascended to the throne of quintessential gateway co-op board game. The first release featured wooden cubes (which seemed just so en vogue at the time), sleek and simple art, and (later on) an expansion that added a "Bio-Terrorist" role and a purple-colored disease. The ascension of Pandemic was such that stores like Target and Barnes & Noble prominently displayed it in their game aisles. My first exposure to it was in 2010 when a few friends at work invited me to play with them during the lunch break. Instantly, I realized the family potential of it; even my young sons could play and enjoy it. When I purchased it and brought it home, my boys appreciated it, though my wife found the theme (and the rapid spread of disease cubes) disconcerting and unenjoyable. Nonetheless, I comprehended the impact of Pandemic in hobby gaming.
As of 2022, there are numerous co-op offerings, such as Gloomhaven, Battlestar Galactica, Robinson Crusoe, Saboteur, Forbidden Island/Desert, and the aforementioned Shadows over Camelot; there are team versus team co-op games like Captain Sonar and Specter Ops; and there are versions of Pandemic that involve making permanent changes to the cards and game board, such as Pandemic Legacy.
Should I trash or treasure Pandemic?
At a Game Weight of 2.47 on Board Game Geek, Pandemic is challenging enough for seasoned gamers to enjoy, yet easy enough to learn to attract casual gamers. It can be played in an hour, which may be a great transition game between two more complex games or the primer game before the multi-hour game starts. Whatever the case, Pandemic is often a suitable choice for any game night.
If I am really hankering to play a cooperative game, though, I prefer the deeper Robinson Crusoe, which has so much going for it: superlative art, lots of mechanics at work, and a weird sense of foreboding that reminds me of the television show Lost (minus the Smoke Monster). An amusing semi-cooperative game I also favor is Between Two Castles of Mad King Ludwig, which compels you to cooperate with your neighbors, but not TOO much.
Because my copies of Pandemic and the expansion are vintage, first-edition versions, I will not be selling them. That iteration of Pandemic is a work of art and fun to unpack and set up. Occasionally, I bring it out to teach Gen Xers and Millennials how co-op games work. There is no shame in keeping this classic, and the box (even with the expansion) is still slimmer than many of my other games, so it doesn't take up much space.
Should you trash or treasure Pandemic?
Despite that, if you own Pandemic, I would venture a guess and say that you may not miss it if you gave it away or donated it. There are many other cooperative games that are good gateway games, fine complex games, or even more cutthroat team versus team games. I am tempted to argue that Pandemic is a bit vanilla, but a game that revolves around disease is just a bit too topical nowadays. In any case, there are enough choices out there to find a co-op game that appeals to you thematically.
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One more thing: due to the ubiquity of Pandemic, you would be hard-pressed to sell it for profit. Most people can purchase it locally at a big-box store, so paying shipping to buy a used copy may not make economic sense. Consider donating it at a thrift store to spread the hobby to others. You may have a friend who is new to the hobby; you could teach Pandemic to that friend and give him the copy. Regard Pandemic as a powerful way to open people up to hobby board gaming, so it would be worthwhile to give it away.