Motorcycle trials, also termed observed trials, is a non-speed event on specialized motorcycles. The sport is most very popular in Europe and the USA.

Trial motorcycles are distinctive in that they are extremely lightweight, lack seating (they're designed to be ridden standing up) and have suspension travel that is short, relative to a motocross or enduro motorcycle.

The event is split into sections where a competitor rides through an obstacle course while attempting to avoid touching the ground with the feet. The obstacles in the course may be of natural or constructed elements. In all sections, regardless of content, the designated route is carefully contrived to test the skill of the rider. In many local observed trials events, the sections are divided into separate courses to accommodate the different skill level of riders, who compete in skill-rated classes. In every section, the competitor is scored by an observer (hence the sport's name) who counts how many times the competitor touches the ground with the foot (or any other part of the body). Each time a competitor touches the ground with a foot (commonly called "dabs" or "prods"), the penalty is one point.

The possible scores in each section consist of 0, 1, 2, 3, or 5. If a competitor makes his or her way through the section without touching the ground with a foot, a score of 0 (called "cleaning the section") is earned. If he or she touches the ground only once, the score of 1 is earned. If he or she touches down twice, the score of 2 is earned. If he or she touches the ground three times or more, the score of 3 is earned - as long as the section is completed without stalling the motor, dismounting, going out of bounds or going backward. If the competitor fails to complete the section a score of 5 (sometimes colourfully called "a fiasco") is earned. The winner is the competitor with the least points at the end of the event. Some events are also timed with penalty points assessed to rate riders.

Trial Riding Rules for riders and observers  
  Allowed Not allowed Penalty points
Footing Brushing past rock or tree. No penalty points Allowed with the maximum penalty of 3 points. Using rock or tree to regain balance will count points 1
Balancing Balancing without footing, Balancing with footrest or bellypan on rock or log Footrest or belly pan on rock with foot touching rock or log. 1 point per touch 1
Failing   Handlebar on ground 5
Rolling back Unlimited Rolling back while footing 5
Hand off handlebar To lift Helmet To restart engine while footing 5
Dismounting Not allowed Handlebars on ground or both feet on the ground on the same side of bike 5
Outside assistance Not allowed Any outside assistance will incur 5 penalty points 5
Sideways hopping Hopping and moving backwards   0
Crossing your line Riding without crossing your own line with both wheels Riding or hopping over your own tracks with both wheels 5
Flags and boundaries Not touching the flags Riding over flags, Passing flag on the wrong side, Floating front or back wheel over flag 5
Moving flags Replace flag in original position or securing flag Deliberate moving to ease section 5
Flag colours red blue yellow white Passing a flag on the wrong side 5
Riding a line Staying within the designated class boundaries Riding wrong line or traversing any other line in the wrong direction 5
Start and Finish gates Starting and exit section through correct gates Missing either start or end gate. Front spindle  5
Starting a section Wait for the observer to indicate to start Enter section before observer acknowledgement 5
Section boundaries Staying within designated boundaries Riding over markers, flags or designated boundaries 5
Arguing with observer Politely enquire Arguments with observer +5
Missing a section Missing and doing it later Missing totally ?
Sequence Doing the sections in numerical order Doing sections out of sequence. What if there is a queue ?
Dangerous behaviour Not allowed Dangerous behaviour like Racing between sections Disq
Obstruction in section Stop immediately and request to redo section obstruction: humans/dogs. Do not ride over them Disq
Signing on and off Sign on and off within the designated time not signing on or off Disq
Time Penalties Staying within the allocated time and penalty time 1 point per minute penalty until cut-off time. Limit per section is 1.5 minutes 1Point/Minute
Time penalties per section Staying within the allocated time Go over allocated time of 90 seconds 5
Time extensions Inform riders and observers Go over allocated time  
Sharing bikes Non national events In nationals Disq
Practicing sections Only after end of penalty time No practicing 2 weeks prior to event or until 30 minute penalty time ends Disq
Moving obstacles Removing glass, wire and dangerous branches Moving rocks and logs within the section boundaries 5
Scrutineering Repairing fault after failure Present bike for scrutineering outside allocated time
  Resubmit bike for scritineering within time Number size 100mm and colour Black on white background
    No lose Spokes screws or bolts
    No gumboots, sleeveless shirts, bicycle helmet or short pants
    No Ball ends on brake and clutch
    Handlebar ends not blocked
    Kill switch or brakes not working