If you or your guild has a tile that is under attack, or is likely to become attacked, you can deploy a card deck to that tile to protect it.
Sending backup to a tile is done just like deploying to a tile. If you're deploying to a tile held by a guildmate (or yourself), the Backup option becomes available. Note that for deploying and retreating backup, the units travel at their normal travel time so be sure to launch in time.
Backup sent to a tile will remain there until any of these happen:
- The deck is defeated in battle
- The tile is abandoned
- The sending fort is destroyed
- The owner of the tile or the owner of the unit retreats the unit
A tile can hold up to 5 backup decks, and a forted tile can hold up to 10. Additional decks can be sent, and the check for free space is done when the decks land at the tile so if a tile is under sustained attack it can be worth sending additional backup even if the tile is known to be full.
For non-forted tiles, the NPCs attempt to repel attacks before the backup is engaged.
To recall backup, select Unit from the map screen. Find the unit you wish to recall, and click Info. Verify that this is the unit you want to recall, and click Retreat.The same method can be used to send other peoples' backup home as well. Your guildmates are not notified when their backup is released this way so you may want to let them know that their deck will be freed.