Rangers in Baldur’s Gate 3 are very versatile combatants. They can engage in melee combat with dual wield or two-handed weapons, or attack from range with both projectile weapons and spells. To make the most of your Ranger, you will need to choose one of those avenues, however, because while Rangers are a solid class, they quickly fall off on power if you try to do too many things at once.

Baldur’s Gate 3 - Ranger Best Build Guide

For my money, the best Ranger build in Baldur’s Gate 3 is Beast Master. This specialization gives you the Ranger’s Companion spell, which allows you to summon an additional party member to aid you in combat. From tanking bears, to damaging wolves and a whole lot more, splitting focus in Baldur’s Gate 3 can give you breathing room that can spell the difference between winning and losing.

I opted to focus on a build that avoids multiclassing for this guide, but if you want to multiclass, I do have recommendations, and you're able to respec and change classes when you see fit, which is a nice bonus.