F Rank, or Free Rank, is an optional rank that anyone can enter. While anyone can enter, it is advised that the player have raised a monster up to at least rank A. Random assortments of monsters from ranks B, A, and S appear (E and D during Freshman's Cup). If the player has sucessfully beaten the entire tournament league in Monster Rancher 2, the player may even see the last member of the Major 4 that they fought.
The prizes of the matches are few due to a lack of actual tournaments. What is available for prizes are the rare Hero and Heel badges, items vital for changing good or evil monsters or a Silver Peach, capable of extending a monster's lifespan.
- If the player's monster is younger than one year old, the tounament will become the Freshman's Cup. If the player's monster is older than six years and three months old, the slot will have the Elder's Cup. If the Player's monster is in between the above ages, the tournament will not appear.
- If the Player's monster has Best as their nature, the Hero's Cup will take the slot. If the monster's nature is Worst, the slot will become Heel's Cup. If the monster is Good, Bad, or Neutral, the tournament will not appear.