A rich industrialist on Solaris Seven by the name of Johnny B. Rich gained a massive windfall from the sale of his brand of hovertrucks all over the Inner Sphere, starting from the Solaris riots when several rioters actually managed to topple a battlemech using his trucks.
The resulting publicity boom brought increased sales, and before he knew it, he was a millionaire, and close to having a billion dollars.
Seeking cheap thrills and kicks, he decided to do something with his fortune, and founded a minor battlemech league in the more rural areas of Solaris.
Seeking a way to have the battlemech contests decided purely on skill, he got his factories to produce a 15 ton lightweight battlemech for use in a game of his own devising. It was to be as cheap as possible.
The Duelist was the result.

The Duelist was constructed around the chassis of an utility mech, and then powered by an internal combustion engine. A small cockpit was installed, which increases the difficulty of piloting the mech.
The armor weighing 3 tons is actually quite formidable for a mech of its class. Its weapons are considerably weaker, due to B. Rich's insistence that he does not want the games to be decided by lucky hits. Consequently, the Duelist's defense far outweighs the offense.
A solitary heat sink provides cooling for the mech, which makes contests quite interesting as pilots have to watch their heat very carefully.

The rules for using the Duelist in games were drawn by by B. Rich himself, and are strictly adhered to. Many observers have caustically observed the games as just being a larger version of soccer or rugby, with violence being sanctioned.
Two teams of eleven Duelists each are formed up on a field a kilometer long and 500 meters wide. On each end of the field is a small 'goal' area, tended to by a Duelist designated as the goalie.
A huge steel ball about 1 meter in diameter serves as the ball, to be deposited into the goal area of the opposing team in order to score a goal.
The game is played much like soccer, except that the ball can be handled as well, and that weapons attacks are allowed. Due to the nature of the ball, any hits on a Duelist by another Duelist will often knock the ball away.
B. Rich sponsors all games, and willing participants only need to register and pay for ther own uniforms, insignia, and training at his simulator center. If additional real practice with the Duelists are required outside of the sponsored time allotment, the team will have pay for the extra rental.
The games take place all year long, in a league format, with the top 4 teams drawn off in a playoff. The winning team of the 'Rich Cup' gets a hefty reward, as well as an all expenses trip to Solaris City to watch the final match of the Grand Championship.

The goalie version mounts a hatchet and an extra half ton of armor by sacrificing the small laser.

Killian "Smokeclaw" (Weaver)
A youth of barely 14 years old when he shot to prominence, Killian is one of the last survivors of Clan Smoke Jaguar, brought to Solaris Seven when he was just 4 years old by one of the many expatriate Jaguar warriors seeking honor on the Game World.
Abandoned at six when his caretaker warrior was murdered, Killian fell into the care of the wrecked social services system of Solaris City. He was shuttled through a succession of orphanages before he ran away at the age of 8.
Making his way to the rural areas of Solaris, Killian worked odd jobs to support himself and earn a living. He eventually made a home for himself in the small industrial town of Eastwick, helping out in a small machine shop. He kept to himself, untrusting and wary of people after his experiences.
In 3070, a technician named Tai Po who was once a trainee in a minor stable decided to try his luck in the Rich Cup. He gathered just about the sorriest group of down and out people around him to form an amateur team.
There was Tai Po himself, trying to raise two children on his own after his wife passed away of cancer. His best friend, a middle aged man still having dreams of making it big as a lounge singer while competing against the karaoke machine. An ex-convict colleague from his workplace with major anger management problems. Sponsored by a fruit seller, they set out to accomplish their dreams.
Along the way, Tai Po saw Killian racking up huge scores in a battlemech game in the gaming arcade, and literally begged him to join their team. Another two technicans who dropped out of a Free Worlds League military academy joined up in the same fashion.
The mess of people with widely disparate backgrounds started to coalesce only when their dismal training in the arcade after a string of losses was interrupted by a drunk and bitter old man, who turned out to be Sammy Best, a mechwarrior who once reached the top twenty in the Championship. He berated them at length, and when it was over they begged him to be their trainer, recognizing that he alone had the ability to help them.
A trueborn of Clan Smoke Jaguar, his genemother Sarah Weaver, a saKhan of the clan, Killian was a natural-born mechwarrior, and he quickly became the cutting edge of their attack. Coached personally by Tai Po and Sammy, who saw in him their redemption and the fufillment of everything they could have been but thrown away by their own poor choices in life, Killian progressed rapidly in his skills.
The team clawed its way into the playoffs, and eventually won the Cup under amazing circumstances. The members of the team used the prize money to start their lives afresh, several members pooling their funds to open a fairly successful business in Eastwick.
Killian was talent scouted by Starlight Stables, and brought to the stable as a trainee mechwarrior only after much discussion of his future with Tai Po and Sammy, who became his legal guardians. Far better than his fellow trainees, Killian now trains with the top ranked fighters of the stable instead, waiting for the chance when he would vindicate his heritage and prove his worth as a warrior.

Duelists have surprisingly been found in a few militia units around Solaris, in addition to those in B. Rich's competition. It seems that the militia have decided that a mech is better than no mech at all, and bought the Duelist for purely peace of mind purposes, though its effectiveness in real battle is well known by everybody.