This page of the Ghost of Tsushima guide answers the question of how to unlock the grapple hook. It is the most important gadget for exploring the game world. We also explain when and how you can use the grapple hook.
How to get the grapple hook?
The grapple hook is unlocked by making enough progress in the main storyline. You must start The Iron Hook main quest and meet Taka at the Komatsu Forge, which was liberated from the Mongols in one of the previous quests. Taka gives Jin a grapple hook, and one of the next objectives of the mission is to "test" the gadget while infiltrate the Mongol camp.
How and where to use the grapple hook?
The grapple hook can be used on white or white and red interactive hook points - the picture shows an example.
The grapple hook icon won't appear on the screen immediately. You have to jump (press X) towards the hook and use the gadget during the jump (press R2). Only then will Jin catch on to the grapple (assuming, of course, that it is within his range).
The grapple hook has three main uses. After catching onto a protruding horizontal hooks, Jin can swing on a rope. He may do this to jump to a remote ledge or to another hook and use the grapple hook twice in a row.
The second category of grapples allows you to climb a vertical wall. You can do this to reach higher ledges.
A third use is grappling the edges of the roofs of buildings. Jin can climb a rope and reach the roof after attaching a hook.
A grapple hook is used mainly in quests, but also to access certain secrets. For example, in order to reach some Shinto shrines, it may be necessary to climb using the grapple hook. Playing in the early hours of the game should inform you, if necessary, that you do not yet have the grapple hook required to climb.