Game description from the publisher:
As the Great Houses of Westeros play their game of thrones, their battles and bids for power necessitate they maintain strong fleets of warships, lest their opponents find their shores ripe for the picking. Naval superiority is the call of the day, especially while the krakens of House Greyjoy sail the coastlines in their longships.
The Chapter Packs from the A Song of the Sea cycle introduce the challenge enhancement mechanism to A Game of Thrones, and Reach of the Kraken allows players to make good use of the new naval enhancement. No fewer than ten characters from Reach of the Kraken feature the enhancement, which allows players to have them join a challenge as an action – even after the challenge's attackers and defenders have been declared!