Can I use Unshakable to use the battle action on a terrain in the discard pile (say Unfamiliar Ground) while there is a terrain already in play at the current battle (say Unfamiliar Ground)?
Unshakable and Terrain (in play)
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
If a Terrain is already in play at the current battlefield, no player can play another Terrain there.
No.
This question caused a bit of discussion about whether it is legal to target a Terrain Action card in your discard pile with Unshakable while there is a terrain in play.
The conclusion was: it is legal to target *any* action card in your discard pile, regardless of whether it has a Battle action you can legally use as for the additional action. The legality of the additional action is not checked until the "Announce the action" step. Unshakable and the targeted Action card are removed from the game regardless of whether you successfully took that additional action.
Alex