Instructions
Start the game and then log into your account. Click the icon that looks like a globe on the top right-hand side of the game screen to bring up the world map.
Click on the search box situated on the bottom left-hand corner of the map and then type "Gamers' Grotto" before pressing enter. This marks the location of the grotto on your map making it easy to navigate to. You'll find it slightly to the north of Falador.
Travel to the "Gamers' Grotto" on your map and then left-click on the cave entrance to enter. Walk down the passage until you reach the four-way split and then take the bottom passage which leads you to a large swirling purple portal.
Left-click on the portal to enter and you will be taken to the "Fist of Guthix" area. Walk to the end of the passage and speak to the large creature named "Fiara" to learn the rules of the mini-game.
Enter the passage to the left to reach the waiting room once you are familiar with the rules. Wait until you are paired up with another player and then compete in the mini-game. In one round you are the hunter, and in the next round the one who is hunted. As the hunter your goal is only to kill the other player. As the hunted you must avoid getting killed while picking up the glowing stone (called a charge) that is lying in the arena and then carry it to the center of the arena where it is charged up.
Keep playing the mini-game until you have acquired 150 tokens. The amount of tokens you receive from the mini-game depends on how many charges you were able to acquire during a match and whether you won or not. Once you have enough tokens speak to "Reggie" who is the shopkeeper close to where Fiara is standing.
Click "Yes I want to see what you are selling" and then scroll down to "Adamant Gauntlets." Double-click the gauntlets to buy them.