What are the rules for Mormon missionaries?

Excommunication in the Church of Jesus Christ of Latter-day Saints (commonly called the "Mormon" church) is quite rare, although it was more common in the earliest days of the Church. The process and rules regarding excommunication are rather specific. The process works like this:

When a Church member commits a serious sin, it is their responsibility to visit with their local congregation leader (a Bishop) to receive counsel and support in repenting of the wrong. The Bishop will discuss the act of repentance with the individual and suggest a course of action. The vast majority of issues discussed with a Bishop require no formal disciplinary action. For more serious sins, the Bishop may choose to quietly place the individual on probation, meaning that they should not partake of the Sacrament (communion) or attend special Temple worship services (different than regular Sunday services) for a period of time until the issue is resolved. For the most serious sins, a "Church Court" is convened, comprised of local Church leaders. The Church Court will meet together and with the individual to decide whether no action, disfellowshipment, or excommunication should occur. Disfellowshipment is a step slightly higher than probation and lasts longer. It means that the individual, while still a member of the Church, may not hold a position in the Church, lead congregations or classes in prayer, or give sermons during worship services. If the individual is male, their rights to perform the ordinances of the Priesthood are put on hold.

Excommunication is the most serious form of Church discipline and must be decided by a Church Court. Excommunication is only possible in cases of murder, adultery, plural marriage (polygamy), incest, having apostatized and become openly antagonistic against the Church, abortion, having a transsexual operation, attempted murder, rape, forcible sexual abuse, intentionally inflicting serious physical injuries on others, fornication, homosexual relationships, child abuse (sexual or physical), spouse abuse, deliberate abandonment of family responsibilities, robbery, burglary, embezzlement, theft, sale of illegal drugs, fraud, or perjury. Those who hold leadership positions in the Church are held to a higher standard than recent converts or younger members. Teens and young adults are very rarely excommunicated for these behaviors, they are usually put on probation.

Excommunication, just like disfellowshipment and probation, is meant to be temporary. While excommunicated members are no longer members of the Church, they are encouraged to continue attending worship services and meet with the Bishop regularly to track their progress. Excommunicated members may be re-baptized and regain full fellowship in the Church if they choose to do so. The process would be the same as if they were a convert to the Church.

You can learn more about the rules and reasons of excommunication within the Church from the "Related Links" below.