Adventure rank in Genshin Impact is leveled by looting chests, completing quests, and tackling world events.
The Adventure Rank in Genshin Impact is a catch-all level that represents your progress in the game. Completing the main, side, and daily quests levels it up fastest, but dive into areas (dungeons), loot chests, and clean up. the lines of play all contribute to this. Almost anything that doesn't directly murder enemies (bosses aside) will give you some form of adventure rank experience.
Adventure rank is important because some mechanics and systems are locked behind it. The most important of these is your World Rank, which evolves the world to provide harder challenges and better rewards. You'll have to overcome an Ascension Quest to actually level up the World, but it won't be available until you reach the required Adventure Rank. Additionally, you cannot tackle certain quests or areas in Genshin Impact without first achieving an Adventure Rank. The commission and distribution system is stuck behind rank 14, and cooperative rank 16.
Additionally, after completing some of the intro story quests, you will be able to speak with the adventure guild representative, who will reward you with items for each rank. That, and the Adventure Log will become accessible, which is a sort of activity and task checklist with even more rewards.
To put it simply: don't neglect your Adventure Rank. Take quests and complete them ASAP to level it up, but also don't forget to loot the various chests scattered around Genshin Impact. You will find yourself climbing the ranks in no time if you do so, at rank 27 you will unlock all the current main features of the game. Good adventure, traveler.
