Intelligence is essential to Elden Ring Runes increase the damage of sorcery spells and other weapons that scale Intelligence, and it is required to master more powerful spells also.

Faith

Incantations and weapons for Faith-scaling require points being placed in Faith as well as learning which incantations are the most potent.

Arcane

Leveling up Arcane brings increases to your discoveries, which means that you'll have a better chance of finding the items you need from the foes that you fight. Certain sorceries and incantations also benefit from this statistic.

What is the best way to upgrade and what are the reasons

Your score increases with every points you add to one of the eight principal stats. Based on the class you chose at the beginning of the game, or on what long-term goals you're hoping to achieve, your stats spread will vary. Melee users and magic users will have entirely different priorities, for instance and secondary and secondary stats to account for when attempting to buy Elden Ring Items build an optimal build.