Yes , it's exactly what it sounds like...
It's the wasteland and people need to be entertained... and there is very few moral constrictions on people now.
Have a system where a player can manage a stable of different kinds of fighting animals.
1. A player could purchase an animal ready to fight.
or
2. A player with the right skill could capture a creature and train it to fight in the pits.
My idea for this is if you want to get right into the pit fighting just buy an animal. But if you put in the time to train your skill you could go out into the world and find Exotic animals to train and fight with. These animals would not be available for purchase in towns. Bought animals can be trained and equipped with armor and weapons . Just that a Pit Dog or Regular Rad Scorpion is not as sixy as having an exotic creature caught in the wasteland.
Could wager items or money on the fights. Would be a system to increase the combat skill of the creature through training by the player. Player could purchase or craft armor for the fighting animals. Same goes for weapons for the Creature. Player would have to invest time and money to have Kennel or Pen where creatures are kept.
Any Creature can fight Any Creature ... it's up to the player to decide if it's worth the risk/reward.
Should be able to have Multiple Creatures at once not just 1 Vs. 1. Large King of the Cage matches with lots of Creatures all at once.... imagine the Mayhem!!
Creatures would be controlled by --> AI+ factor in the skill level of the players skill in training fighting creatures+ any armor and weapons creature has+ skill and experience the creature gains as it accrues more fights.
Player has no Direct control once the fight has started.
Could be TWO kinds of fights...
1. Knockout fight... when one creature is down to 5% health lets say the player "Throws in the towel" The player loses the fight and any bets, items, money wagered but keeps the creature alive. Player has to spend resources and time to Heal Creature back to fighting strength.
2. Death fights. Players agree before hand that this fight will be to the death. If animal is killed in the pit it dies and player can salvage the hide for armor and materials ( like skinning in the open world). Or player can have the creature stuffed and mounted as a trophy of a fighting animal the player once owned. Can be put in player house for example.
Could have a league system. Little small towns have little small fights in back rooms. All the way to Major events held in "Main" cities or areas that are broadcast over the server and could have people come to watch the fights and bet on them. Top level fights would attract lots of people since there would be very Exotic , rare Creatures fighting that many people may not be able to see anywhere else.
For example could have a Two-headed DeathClaw that is completely armored up and trained up with rippers attached to its claws Vs. A very rare Giant Super Rad Scorpion that has power fists attached to its stinger. Gawd Damn!!!!!
I think this would be an excellent way to provide end game content that literally never ends! Make a name for the player by striving to be the best pit fighting manger. This is a form of PvP combat where the player does not have to worry about perma death. I think this would be very hard to hack with since the player would have no direct control of the animal once the fight starts. Hunting for rare and hard to capture Creatures in the Wasteland would be an amazing adventure.
The player would have to Capture the Creature Alive in the Wasteland. Not kill it. That means using stun darts, tranquilizers, traps, paralyzing rayz... etc... For the really exotic and tough creatures probably would need a group to hunt and Capture the Creature. This would give guilds an interesting quests to try to find the most exotic and difficult creatures to capture and train and fight with. The Creatures record would be able to be seen somehow... wins losses draws.
Player should be able to sell and trade creatures as they see fit. MMO's... MMO's never change...