Halo Infinite

As soon as you start the campaign, you can use the grappleshot with your ability button (for me, it's ). Simply do 50 grapples-and-tugs (i.e. grapples that actually happen, and don't 'break' the grapple), and you'll get the achievement.

The Grappleshot is the very first armor ability you unlock in the game, you'll have it equipped from the start. Using default controls, the button to use your armor ability will be the Right Bumper. To use it "successfully" you need to shoot the Grappleshot without the line getting severed, which can happen if you hit a Jackal's shield with it, and without firing your weapon while the Grappleshot is still gong, etc.

Essentially, you should have a brief moment of cooldown before you can use the Grappleshot again. If that cooldown starts, you've used it successfully. You can grapple enemies to pull yourself to them and melee them, you can grapple items like weapons and fusion coils to arm yourself with them, you grapple into vehicles, and you can also grapple most parts of any map to move yourself with momentum in certain directions. I do not believe dying after grappling a certain amount of times will reset your progress. Grapple 50 times, and this one is yours. Happy hunting!

You'll probably unlock this just by playing the game considering how much you will need to use the Grappleshot. If you want to speed it up, once you have the Bandana skull, load one of your saves with it that skull active. This removes the cool down for equipment. Then just keep pressing the button to use the Grappleshot over and over until this achievement pops. That's it! Also works great for all the other equipment achievements.

This achievement is potentially bugged--I was able to obtain it after using the grappleshot 50 times regardless of whether or not the use was successful, so just spam the grappleshot when you get it and see if the achievement pops.