Disc Golf
From Wikipedia

Disc golf is a disc game in which individual players throw a flying disc into a basket or at a target. According to the Professional Disc Golf Association, "The object of the game is to traverse a course from beginning to end in the fewest number of throws of the disc."

Rule Difference with ball golf and disc golf:

• In ball golf, the player can only carry 14 clubs. Disc golf has no rule concerning how many discs a disc golfer can carry. Also, disc golfers may add discs to their bag during the round, which is not allowed in ball golf.

• Whereas club golfers must "play it where it lies" on the ground, it doesn't work the same with disc golf since the disc is thrown and not struck. Disc golfers must have a supporting point (usually a foot but can be any part of the body) on the playing surface within 30cm behind the front edge of where their previous shot landed (if inbounds) at the point their next throw is released. This allows the disc golfer to lean to the left, or the right to establish a better angle around obstacles. His 'pivot' foot must remain behind his marker however. A special mini-disc is usually used to mark the previous lie on the ground, however the use of a mini is only required if the player would like to use the same disc they just threw or if they are moving the lie.

• In disc golf, it is acceptable for a player to 'fall' in front of his lie. The motion of throwing the disc often involves a significant amount of force, which can cause a player to be off-balance. As long as his 'plant' or 'pivot' foot is behind his marker when he releases the disc, he may fall in front of the marker after the release. This allowance does NOT apply to putting. A throw is officially considered a putt in disc golf if the lie is marked within what is known as 'The Circle'. This is a circle with a ten meter radius, with the pin at its center. After putting, a disc golfer must demonstrate balance with his plant foot, before they may step away from his marker. However, like golfers may putt from the fringe, rough or fairway, most disc golfers still use a putting motion on shots that are longer than 10 meters, often called "being out of the circle" or "being outside." The player may follow through on these shots and many players develop a jump putt where the golfer jumps towards the target. This allows a combination of the accuracy that putting provides and more power on the putt.

• Falling putts (when the player follows through [as described above] on a putt 10 meters or shorter) and foot faults (when a player does not release the disc behind their mark or within the required distance of the mark, when a player has a part of their body touching the ground on release past their mark or when their tee shot is released from off the teeing area) are penalized in a unique way. The first offense is not penalized a stroke, but the golfer is required to re-throw the shot and then is warned for the offense. Any subsequent fouls, however, are penalized one stroke and the golfer must re-throw.

• Disc golf doesn't have "hazards" as defined in ball golf. Bodies of water, park roads and areas of cement are typically defined as out-of-bounds in disc golf, however, sometimes these are not. Most courses define these areas as out of bounds or in bounds on tee signs at each hole, however, there is no universal standard for these. As in ball golf, any out-of-bounds shot is a one stroke penalty, however, the rules for spotting the lie for the next shot are quite different than those in ball golf. If a throw lands out of bounds, unless defined by the hole, the thrower has the option of playing from the previous lie, or playing from the approximate spot where his disc crossed into the out-of-bound territory. If he chooses to play from where his disc crosses out-of-bounds, he may take a one meter relief from the out-of-bounds area, even if it puts him closer to the pin. The rules do not permit a player to have a supporting point touching out of bounds on release so this is the reason for the relief. If a player lands within a meter of the out of bounds and is in bounds, he is still granted this relief for the same reasoning. This relief is an option, the only rule regarding this is when the disc is released. Most golfers use this rule to their advantage to make putts closer or to improve their lie. Some holes may require a throw from a Drop Zone. If that is the case, the thrower moves to the drop zone to play his next shot. A disc is only considered out-of-bounds if it is completely surrounded by out-of-bounds - if any part of the disc is touching in-bounds, then the lie is playable.

• Another difference is the optional penalty for a disc that lands more than 2 meters above the playing surface. The course designer may specify that on particular trees, holes, or the whole course, a disc landing above 2 meters will receive a one throw penalty. This is known as the 2-Meter Rule. If not specified, there's no penalty for a disc landing any height above the ground. In ball golf, it's likely a player will need to take an unplayable penalty if their ball lands above the ground. On the other hand, balls are much less likely to remain stuck above ground than discs are as they fly through trees. When the disc is stuck above ground (including on top of baskets and those that land in the wrong the basket) are to be marked directly below the disc. Even if the disc is not retrievable, as long as the player can identify it, he is not penalized (assuming the 2- meter rule is not in effect). A tournament director has the option of enforcing the 2-Meter Rule regardless of whether or not the course enforces the rule. Many casual disc golfers often choose whether to play with the 2-Meter Rule at the beginning of a round.

• Disc Golf holes may also have what are known as 'mandatories' or what are commonly called "mandos" These are obstacles that a disc must pass in a certain way. For example, a tree may be marked as a 'right mandatory', meaning a disc must pass that tree on the right side. Failure to hit a mandatory is a one-stroke penalty, and the thrower must play from his previous lie or a drop zone if provided. Mandos are usually put in place to force a player to play down a fairway instead of down another fairway to help with safety.

Safety: Disc golf is usually played in a public park, thus bicyclists, hikers, children playing and campers are often on the course. On some courses, such as on a college campus, athletic activities often take place on fairways. Disc golfers have to be very careful to avoid pedestrians, and it is a generally accepted rule that pedestrians have the right-of-way.