Forests of Training are high difficulty, 0 stamina, 20-stages long battles permanently available at the Extra Isle. Upon completion, the player receives a special item, usually a new ship (and a rainbow gem). A new Forest of Training is added to the game every few months.
In those quests you won't obtain any reward from the enemies except the one-time clear reward for each stage (ship+gem). You cannot use a gem to revive upon defeat, it's do-or-die.
List of forests
Currently the following Forests are available on Global:
- Forest of Training: Hawk (aka Mihawk Forest). Added: July 2015. Reward: Coffin Boat
- Forest of Training: Beard (aka Whitebard Forest). Added: December 2015. Reward: Moby Dick
- Forest of Training: Pheasant (aka Aokiji Forest). Added: August 2016. Reward: Aokiji's Bicycle
- Forest of Training: Flame Fist (aka Ace Forest). Added: October 2016. Reward: Striker (Ship)
- Forest of Training: Sun (aka Jinbei/Jimbei Forest). Added: Reward: December 2016 Sun Pirates Ship
- Forest of Training: Red Hair (aka Shanks Forest). Added: December 2016 Reward: Red Force
- Forest of Training: Kami (aka Enel/Eneru Forest). Added: January 2017. Reward: Ark Maxim
- Forest of Training: Snake (aka Boa Forest). Reward: Added: February 2017. Kuja Pirates Ship
- Forest of Training: Heavenly Demon (aka Doffy Forest). Added: May 2017. Reward: Donquixote Pirates Ship
- Forest of Training: ROOM (aka Law Forest). Added: October 2017 Reward: Polar Tang
- Forest of Training: Monkey (aka Kizaru Forest). Reward: Kizaru's Cannonball
The following forests are not yet available on Global, but are available in Japanese version of the game (and likely will become available on Global in the future):
- Forest of Training: Nose (aka Usopp Forest). Reward: Karasumaru Ship
There was one older forest which have been removed from the game. It provided no reward. See Training Forest (no treasure).
Difficulty
While in-game, all Forests are ranked equally in terms of difficulty, in practice older forests are easier. Hawk, Beard and Flame Fist are considered easiest. Several forests can also be completed with reasonably forgiving zombie-teams if you have the right subs and/or ships.