A landfall ability triggers whenever a land you control enters for any reason. It triggers whenever you play a land, as well as whenever a spell or ability puts a land onto the battlefield under your control.

A landfall ability doesn't trigger if a permanent already on the battlefield becomes a land.

Whenever a land you control enters, each landfall ability of the permanents you control will trigger. You can put them   on the stack in any order. The last ability you put on the stack will be the first one to resolve (As a result, you can have those abilities resolve in the order of your choosing.).

The Ring gains its abilities in order from top to bottom. Once it gains an ability, it has that ability for the rest of the game.

Each time the Ring tempts you, you must choose a creature if you control one.

As the Ring tempts you, you get an emblem named The Ring if you don't have one. Then your emblem gains its next ability and you choose a creature you control to become (or remain) your Ring-bearer.

Some spells and abilities that cause the Ring to tempt you may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won't resolve. The Ring won't tempt you.

Each player can have only one emblem named The Ring and only one Ring-bearer at a time.

The Ring can tempt you even if you don't control a creature. In this case, abilities that trigger "whenever the Ring tempts you" will still trigger.

If the creature you choose as your Ring-bearer was already your Ring-bearer, that still counts as choosing that creature as your Ring-bearer for the purpose of abilities that trigger "whenever you choose a creature as your Ring-bearer" or abilities that care about which creature was chosen as your Ring-bearer.