A "LD Rally" is essentially a scavenger-hunt, photo-bonus style event performed on a motorcycle. A rally is usually led by a "rallymaster" who may be a single person or a cooperative effort of a small team. Most operate under the same premise:

A rider is given a list of locations.  At each location, a rider must perform some task.  The most common task is to take a picture of an object, a sign, or perhaps a landscape.  This picture typically contains a "rally flag", some device with a unique number which is assigned to that specific rider identifying them as the person taking the picture.  Other options may also be to locate specific information located on a sign or historical marker or perhaps buying an item and getting a receipt for that item.

Each location, referred to as a "bonus location", is worth a different amount of points.  The points are usually varied in amounts based on the difficulty of getting there or the rallymaster's desire for the rider to go there.  There are numerous locations.  Each rally has a time-limit.  There is never enough time for any one rider to visit every single location, so the rider must carefully plan an executable route which allows them to gather the most "bonus points" and still finish in the time allotted.  If a rider is late to the finish, they are disqualified and declared DNF (did not finish).

These are not races.  There are no points or benefits to arriving to the finish early.  Most current rallies actually prohibit speeding and penalize riders (or disqualify them) for excessive speeding.

These are not endurance events.  Yes, a rider must balance route planning plus riding ability, but most rallies offer significant points for resting and stopping to eat.  Locations are situated so that the rider typically stops multiple times a day.  Riding for hours and hours without stopping is actually discouraged.