We are looking at all the rules concerning the jack in the official rule book. Yes there is one! Handy to know all of these as it may stop you from losing a game one day.
Article 9, Dead Jack during an end
The jack is dead in the following 7 cases:
1) When the jack is displaced into an out of bounds area, even if it comes back on to the authorised playing area. A jack straddling the boundary of an authorised terrain is valid. It becomes dead only after having completely crossed the boundary of the authorised terrain or the dead ball line, that is to say, when it is entirely beyond the boundary when viewed from directly above. A puddle, on which a jack floats freely, is considered to be an out of bounds area.
2) When, still on the authorised terrain, the moved jack is not visible from the circle, as defined in article 7. However, a jack masked by a boule is not dead. The umpire is authorised to temporarily remove a boule to declare whether the jack is visible.
3) When the jack is displaced to more than 20 metres (for Juniors and Seniors) or 15 metres (for the younger players) or less than 3 metres from the throwing circle.
4) When on marked out playing areas, the jack crosses more than one lane immediately to the side of the lane in use and when it crosses the end line of the lane.
5) When the displaced jack cannot be found, the search time being limited to 5 minutes.
6) When an out of bounds area is situated between the jack and the throwing circle.
7) When, in time limited games, the jack leaves the designated playing area
