Specific tasks throughout the game unlock different enchants.

When entering a new world the player will start without knowing any enchantments. To learn the enchantments they have to complete specific tasks that link to the enchantment they are looking for. For instance to unlock the ability to get frost walker you have to kill a stray, or to unlock aqua affinity you must beat an elder guardian.

The range of difficulty in obtaining the enchants could vary and maybe even be linked to difficulty levels. Also when finding enchanted books/armour in chests any not yet learned could appear with the unintelligible writing you see in the end credits, however still give you the effects of the enchants.

The idea of all this would be to give the game more challenge in the early parts and give the player more of a reason to go out and explore and to hunt for the different effects. With the example of the stray it would also give a better use of the mob as well as making things like ocean temples worth going into in more than just getting sponge.

I would love to see more incentive for adventure in the game and am also very interested to see what ideas people have for the different ways you can obtain the enchants.