Obstacles is the preferred term. In a CDE, the obstacles are the last portion of the Marathon Course. In an ADT, that is the only portion of the marathon that is used.
An Obstacle is comprised of a series of “gates” that are set up in a defined area that may have natural elements like trees, or man made fences, upright poles, barrels, barriers made from other objects, and so forth. The gates are lettered A through E. A red letter goes on the right side of a gate, and a white letter on the left side, to show the required direction of travel (red must be on the right to pass through a gate in the correct direction), and to define the sides of the “gate.”
The level of the competitor determines which of the gates must be negotiated correctly. Training Level is required to do A, B, and C, for instance. There is also an “In” and an “Out” and time is taken in the obstacle as the horse nose breaks the “In” gate, and until the nose passes the “Out” gate. For the time to count, all required gates must be taken in the correct order (A, then B, then C) and in the correct direction. Gates become “dead” after they are driven correctly, and may consequently be redriven in any direction to get to the next required gate. Corrections of course may be made, but add penalty points to the score. Usually, an ADT uses four Obstacles, or may use two and drive them twice.
The elasped time in all Obstacles is converted to penalty points by multiplying the time by .25. Penalties in Obstacles are added to the scores for the other parts of an ADT to determine a final penalty score.
EXAMPLE OF AN OBSTACLE