If the Chosen One goes into the Jungle Gym and talks to Stuart Little, they can box. A character with a Strength below 6 or female one has to pass a relatively easy Speech check. They will meet four increasingly difficult opponents: Joqq ($50, 500 XP), Pete McKneely ($50, 750 XP), Evan Holyfeld ($400, 1,000 XP), and The Masticator ($1000, 2,500 XP) (if he is killed, they will face Xander Holyland instead). This is assuming that the Chosen One gets 50% of the winnings; with Speech 76% and Barter 76% the Chosen One can get 75% instead. The Chosen One can also get kill-experience (XP) for any boxers beaten to death; this should happen some of the time and counts as a knockout. Other ways of winning include: "normal" knockout (if the Chosen One score a critical hit that knocks their opponent unconscious or if they get a critical failure), technical knockout (if the Chosen One makes him flee), and points (if the Chosen One somehow manages to make a fight last 12 full rounds and win the majority of them by landing more punches than their opponent). If they win four matches, the Chosen One gets the Prizefighter reputation, which lets them empty the gym lockers, making the Chosen One popular in New Reno and gives them an extra +5% bonus to their Unarmed skill.
Should the Chosen One lose a fight or kick the boxers, they must ask Little for a rematch immediately or they won't get another chance. They will then go up against another boxer (the Chosen One's royalties will drop to 25%, but the XP gained is the same). Little can only be convinced to give one more chance (unless a bug is exploited), which means the Chosen One can fight five matches in all, and there's a tempting reason to do that (see notes below).
At the start of every match, if the Chosen One has either kind of gloves, they get a permanent +3 bonus to Damage Threshold for normal damage (to a maximum of 100), -1 for plasma and explosive damage, and a bonus to Damage Resistance (DR) for each listed damage type except fire (to a maximum of 90%). If Chosen One only has normal gloves, they get +1% DR for all four types, but if Chosen One has plated ones, they get +2% for normal damage, +5% for laser damage and +1% for the others (there's also a -1% penalty to Chosen One's unlisted EMP resistance, but this doesn't matter in the least; the electricity resistance is unaffected).
The Chosen One get to keep these bonuses even after losing a match. Therefore, in the fourth match, the Chosen One can kick the opponent, ask Stuart Little for another shot, then win the final match (the Masticator's replacement is significantly weaker and doesn't bite) to get a fifth toughness bonus.
The bonus from boxing match is considered as a bug that add weapon attributes to the DT/DR. For example, the normal DT comes from action point cost, laser DR from max damage (therefore 5 for plated gloves, while 1 from normal gloves).
Switching to kicking or dealing a blow without the boxing gloves results in disqualification.
If the Chosen One keeps fighting and has an Unarmed skill at about 160% or higher, they may end up biting off the Masticator's ear.
The Masticator can also bite the Chosen One's ear - reducing Charisma by 1 and adds the ear in inventory.
A Chosen One with an Intelligence below 4 can box providing they are male and have a Strength of 6. Aside from getting no pay and no rematch, things work the same. Female characters or male characters with a Strength below 6 have to persuade Stuart Little to box.
If the Masticator is too difficult to defeat, it is possible to go in the basement of Shark Club and kill him there for 1000 XP though losing 5 Karma. However, he will be replaced with Xander Holyland in the ring.