Medieval monasteries had a serious problem. Instead of 100% focusing on their spiritual and earthly duties, many monks loved besting each other at chess. The Medieval version of “video games cause violence” was, “playing chess leads to blasphemy.”
Things got so bad that chess was forbidden many times throughout the medieval period. However, monks were so addicted that often they found creative ways to hide their boards and pieces. Lanercost, a monastery in the UK, features gameboards scratched into the stone of the windowsills for bored monks to play. And the foldable chessboard, which could be disguised as a book and held a compartment for pieces, was developed that way. In a sense, portable Chess was the Gameboy of Medieval Times.
If you’re writing any kind of Medieval fiction, throwing in a chapter about the chess controversy may be a great way to add an extra layer of realism to your work.
And in case you’re wondering, it wasn’t just the Christians who had chess-related troubles. Both Christian and Muslim religious authorities frowned upon it and repeatedly tried to ban it.
In 680, the 50th rule of canons was interpreted as forbidding chess.
In 780, the caliph al-Mahdi wrote to Mecca religious leaders to give up chess played with dice.
In 1005, chess was banned in Egypt and all the chess sets and pieces were ordered to be burned.
In 1061, Cardinal Damiani (1007-1072) of Ostin forbade the clergy to play chess. He even wrote to the Pope complaining that chess was being played by some clergy and laypeople.
In 1093, chess was condemned and forbidden by the Eastern Orthodox Church.
In 1125, the Eastern Orthodox monk John Zonares issued a directive banning chess as a kind of debauchery.
In 1128, St. Bernard of Clairvaux (1090-1153) forbade the Knights Templars from playing chess.
In 1195, rabbi Maimonides (1155-1204) included chess among the forbidden games.
In 1208, the Bishop of Paris decreed that chess be banned from the clergy.
In 1240, the Worcester Synod of England forbade chess to the clergy and the monastic orders.
In 1254, King Louis IX issued a religious edict forbidding chess as a useless and boring game. One can be excused for assuming he was a rather poor player, even though he is considered one of the greatest French kings, having consolidated the Crown’s control over the great lords, proved his passion for justice, and gone on not one but two crusades.
In 1260, King Henry III instructed the clergy to leave chess alone.
Around 1280, chess moralities were written which began as sermons. These chess moralities rivaled the Bible in popularity and number of printings. It is hardly surprising, then, that the Archbishop of Canterbury threatened in 1291 to put the prior and canons on a diet of bread and water unless they desisted from playing chess.
Priests were forbidden to play chess up to 1299.
In 1310, chess was forbidden to the clergy in Germany in a decree from the Council of Trier.
In 1328, some Jewish leaders allowed chess to be played, but not for money or gambling.
In 1329, chess was banned by the clergy in the Synod of Wurzburg in Germany.
In 1375, King Charles V of France, under the influence of the church, prohibited chess. Yes, again.
By 1500, however, things started to turn around. Chess became a recognized pastime for Jews on the Sabbath. And in the 16th century, St. Teresa of Avila (1515-1582) was proclaimed patroness of chessplayers in Spain, perhaps in an attempt to finally legitimize it in the eyes of the church. And several Popes enjoyed the game: Popes that played chess included Pope Leo XIII (Gioacchino Pecci), Pope Gregory VI, Pope Innocent III, Pope John Paul I, Pope John Paul II, and Ope Leo X.
However, this newfound pro-chess attitude was hardly universal. In 1551, leading clerics of Russia compiled the Stoglav Collection which included the prohibition of chess.
In the late 16th century, clergymen in Russia associated chess with witchcraft and heresy.
And the Puritans greatly disliked chess and discouraged any chess play.
Many thanks to Jens Schuetz on Quora for the information!