One of the last things to vanish from the Petroleum Era were the great sports venues. Most of the massive buildings raised to house the massive games for the massive crowds fell into disrepair, or were taken over and converted into the commons of post-Petroleum era urban villages. The sports themselves continued on after a fashion, in a way that would seem familiar to anthropologists and cultural observers. In the Second Renaissance autons became common, and skeletrons filled out military units. These robots were built in large numbers, and eventually, large numbers of these machines became obsolete.
While large numbers of the obsolete machines were recycled, there were still an impressive number of the machines left, and if there is something mankind is good at, it's smashing things. Then, someone started throwing rules into the smashing of things.
The Demolition Ring
The Demolition Ring started as nothing more than autons being used in prize-fights. This began small, in after hours, on work sites. The fights started when robot handlers and foremen had a small number of semi functional autons that were slated to be decommissioned or outright scrapped. Since they were going for the scrap heap, there was no issue over the condition of the machines when they arrived. What started as a small number of specialists blowing off steam after long shifts quickly grew into something larger.
Appearance: The Junkyard Boxer is a minimal humanoid chassis and power core, typically a power cell. This sort of auton was very common, but when brought into the scrapyard and junkyard rings, the robots were stripped of their tools, and crude armor was welded over the vulnerable points on the chassis. As such each of these autons was functionally unique, with hand crafted (junk) armor and creative programming upgrades.
With limited ability to inflict damage, and fairly robust armoring, the battles between junkyard bots could last a dozen rounds. This made for a major social event, entertainment for the working class, and a place for underworld elements to make money from running gambling pools and betting books.
Claiming Matches: In the early years of the demolition boxing it was common for fights to be claiming matches, with the victor of each match being for sale, at a preset price. This was seen as a way to keep things interesting, and to keep a few competitors with more money than others from dominating the sport. The carnage remained high, and innovation rose to keep the machines on their feet without spending large amounts of money. A body of skill grew around this patchwork robotics, and robotic hand to hand combat.
Tournaments: As the sport progressed, there were demolition derby style tournaments, where instead of a handful of fighting autons, dozens or more would be brought together for larger displays and matches. These were freed from the limits of the claiming matches and the character driven fighting machines started to rise in prominence. The fighting metal started to overshadow the operators controlling them. That let teams grow, with more specialized and dedicated machines being cobbled together and scratch built. It was a halycon era for the sport as a small number of people, with a 'bot and a few thousand credits could get into the ring and win some matches and make a name for themselves. There were a plethora of family owned teams, corporate franchise backed machines, and others who got in on the basement level and rose to prominence.
The Major League: From the tournaments rose regional fighting organizations, and from the regionals, nationals, and from the nationals, there grew a world league. As the sport spread out from the American component of the Atlantic Federation, it found fertile soil around the world. Japan, China, California all jumped into the sport. Other nations followed, remaining backwaters with minor presence in the world league, but strong on their internal levels. India, the USSA, and the European DMZ were thrilled.
The World Championship League is dominated by megacorp backed teams, with the most prominent teams being associated with military contractors, auton and skeletron manufacturers, and specialized fighting robot producers. The autons that step into the ring are some of the most sophisticated machines on the planet, one of a kind, and in addition to the revenue they generate fighting, they have merchandising rights, fan clubs, and the like.
Major League Sports
Several major sports dominated in the Petroleum Era, and these sports remain popular, namely Football, Basketball, Baseball, as well as somewhat lesser scale gridiron, tennis, golf, and ice skating. These sports declined in the second dark age, but some, such as football flourished, even in North America where the sport had long remained a maligned and neglected cousin to Gridiron. During the Second Renaissance, these sports were used as glue to start pulling various nations together, and leagues and venues were restored. As the human leagues formed, it was not long before augmented leagues formed, followed by robot and robot proxy leagues. The human leagues are the largest, and have the largest draws as these sports are very close to the common man. The Augmented leagues are the smallest, as creating a balanced field between cyborgs, armatures, clones, genetic mods and parapsychics is laughably difficult. The Robotic Leagues are popular, but more limited in scope.
Robotic Football (soccer)
The great game, played out on hallowed ground, nothing more than men testing themselves against each other with nothing more than a pair of goals and a single leather ball. The official sport of the Atlantic Federation, the unspoken official sport of the planet, with some of the fiercest rivalries being heated matches between nations that have seen warfare in the past. The biggest game of the year is always and without fail the match between Brazil and the Caribbean League, with riots often breaking out where the game was played.
In the robot league things aren't quite as intense, but the matches are much more violent. The rules are softer, allowing for 225 to 275 kg robot players to engage in full contact football. Football 'bots are large and impressive machines, with a very dynamic chassis, and a large degree of mobility through the limbs. While this can be taken for granted, from a programming and technology standpoint, it is an impressive feat getting a robot to run. It took over a century before engineers were able to get a robot to stand and toddle about on it's own without crashing.
Football games are played out on a 50% larger field, and rather than a small leather ball, the robotic league uses a solid rubber ball massing a hefty 30 kg. The machines playing the game have to be not just fast, flexible and agile, they also have to be tough enough to handle the mass of the ball flying around, stopping it in the air with their chest, knees, feet, or even head without taking damage. Likewise they have to be able to survive collisions with other robotic players.
Rather than having series of robots designed for every sport, it is fairly common for a smaller number of machines to be kitted out for various sports, and have their mass and size scaled up and down as needed. The robots used to play basketball, Iron Hockey, baseball and so forth are variations on the dynamic sports model used in football matches. These have cosmetic modifications, but stripped of the outer shell, a base'bot, a basket'bot, and foot'bot are all functionally the same machine, though some tend to be more robust (foot'bot), others more precision and targeting oriented (base'bot) and so forth.
Tennis and Golf 'Bots
The Tennis and Golf series bots are different, as these machines don't require the same robust build and can be much lighter constructed. As such, they are smaller, and could cost less if more attention wasn't paid to their exterior. Both genres are predominated by gynoids, female robots, and as much effort goes into their physical appearance as typically goes into the design of a sports car body.
The old American sport of 'Football' better known as Gridiron is still played, and the robot league is dramatically more popular than the human league. Much like the old style fighting tournaments, robot gridiron games are more akin to a 10 on 10 fighting match with a 100 kg solid core missile being thrown around as a focal point. Rather than a serious sports league, there are a dozen teams that play, and the main product is merchandising for said teams. The cost of keeping so many machines functioning in such a violent environment has actually caused some military viewers to be glad that in times of war, the enemy is really only going to shooting at you, and that is much less violent than a game of Gridiron.
The typical Gridirion auton tips the scales at just over a ton, and is armored like a military assault vehicle. They have a lifespan of approximately 12 minutes of play time before being retired for major repairs.
Cheerleading, Gymnastics, and Ice Skating
Predominantly female oriented sports, these venues are dominated by gynoids, with the biggest backer being the sexbot manufacturers. There are few options for better coverage of the new models than to have a dozen or more in skimpy sports outfits dancing and prancing around to demonstrate how not like a stereotypical auton they are. This has caused a degree of consternation in the sports mentioned, as the robots are seldom more than commercials for sex toys.
The largest venue for cheerleading is the football games, and various manufacturers vye for the chance to be the supplier of cheer'bots for the games. Winning this contract can make or break a manufacturer, propelling them into the big time, or send their stock tumbling in value.
The Other Side of the Coin
The Cosmic Era always has a dark and cynical side to it, and the realm of robot sports is no different, though it's angle is less nefarious and more pragmatic. The robotic sports industry produces a number of things that are valuable for the powers that be in the Cosmic Era.
Morale: sports are and have always been the circus half of the bread and circuses. A large group of people across demographic boundaries can be boosted by their team doing well, just as they can be discouraged by a run of bad luck or worse, scandals and embarrassments.
Pilots: The people who guide, remote pilot, or even inhabit a sports bot through the CogNet are already well enough experienced with controlling a robot body to function as mecha pilots, or power armor pilots (either remotely or the cockpit in chest heavy power armors). Gridiron retains its popularity since many minor league gridiron remote pilots are able to quickly and intuitively pick up controlling mecha and other assault vehicles when they are unable to compete in the major league teams.
Mechanics and Technicians: The people who work on the ground keeping the machines together between rounds, or quarters, or even plays are valuable for their ability to think quickly and flexibly, traits that are valuable in battlefield repair operations.
Money: Sports generate huge amounts of revenue, this has not changed.
Manufacturer Support: Some military contractors have sub-divisions that do nothing but make sports bots, and there is a mixing of technologies between the two groups. Innovations in the sports leagues can translate to major updates or leaps forward in designing things like skeletrons, non-sport autons, and vehicles like mecha and power armor.