Alea evangelii (Game of the Gospels) is a member of the tafl family of games. Known from an illustration and account in Latin in an eleventh-century Irish manuscript where it is given a Christian scriptural context, the game is played on the intersections of an 18 by 18 squares game board (i.e. a board identical to a standard 19 × 19 grid board for playing Go). This is larger than that of most tafl games.

The manuscript, Corpus Christi College ms. 122 (folio 5 verso), attempts to give scriptural meaning to a hnefatafl variant, and, though the layout is unwieldy, its proportions are also found in a game board fragment unearthed at Wimose on the Danish island of Funen.

Manuscript CCC MS 122 is composed of 117 pages. It includes three sections: the ten Eusebian Canons (or tables) representing how each Gospel agrees with or differs from the others; the "Alea Evangelii" diagram and two pages of explanation in Latin; the Vulgate Latin version of the four Gospels, preceded by St. Jerome's prologue.

The manuscript is written in an Irish hand and is commonly dated to the eleventh century. The description of the game states that it was invented at the court of King Æthelstan of England (924–939) by two learned men: an anonymous Frank and Israel the Grammarian, one of the leading European scholars of his time. The diagram and its explanation were brought to Ireland by Dub Innse, bishop of Bangor (d. 953).

A photograph of the game is the frontispiece of The Times of St Dunstan by J. Armitage Robinson, who also reproduces and discusses the text. The captions that label the different sides of the diagram are in Latin with a note partly in Irish. Robinson copied an error by the eleventh-century scribe describing one of the inventors as a Jewish scholar at Æthelstan's court, and the error has been copied by modern scholars. The medieval Latinist Michael Lapidge pointed out that "Israel" is not a descriptive phrase but a reference to Israel the Grammarian.

Each of the four corners and borders of the diagram is assigned to one of the four Evangelists. 67 pieces are derived from the Eusebian Canons: each Canon defines a number of pieces corresponding to the square of its number of columns. Pieces defined by a specific canon are grouped together on the board: such groups are labeled by a cross and the number of the corresponding canon.

Four more pieces are painted in red (all the others are painted in black) and in the manuscript are mentioned as "different men" (varios viros): two of these four pieces are assigned to the Evangelist John (N14, F6), the other to Mark (N6, F14). The four “different men” are also labeled on the board as related to the passion of Christ. One of the black pieces (E13) is referenced in the manuscript as "the primary man" and "belongs to none of the evangelists"; it represents "the Unity of the Trinity", the one purpose of the four evangelists. Finally, "the figure 1 in the middle of the alea signifies the indivisible substance of the Trinity, or the supremacy of the first canon".

The 16 pieces of Canon I form the diamond at the center of the board. Canons II, III and IIII, together with the four "different men" and the "primary man", form the circle surrounding the central diamond. Canons V, VI, VII, VIII, IX are organized horizontally along the lines of the board. The four pieces corresponding to each of the four Evangelists in Canon X are placed in the four quadrants of the board (C14, Q14, C6, Q6).