The Tree Sentinel is the first boss Elden Ring players will encounter on their journey through the Lands Between, but that doesn't prevent it from being a doozy of an enemy. Most players won't be able to fight the horseback menace when they first encounter it, requiring a few levels before they have a shot at taking him down.
But if you're feeling ready to take on the Tree Sentinel, here are some tips on how to approach the fight.
Preparing for the Tree Sentinel Fight
The Tree Sentinel is particularly resistant to slashing damage, fire damage, holy damage, Frostbite and Blood Loss. If you have the chance, you'll want to target him with lightning attacks. That could mean using Lightning Grease — which is relatively rare, and unavailable to craft until late in the game — or by adding a lightning Ash of War to another weapon.
Melee Strategy for the Tree Sentinel Fight
Maybe the easiest way to fight the Tree Sentinel if you're planning to use melee attacks is to employ a bit of horseback combat. When riding your horse, it becomes much easier to ride in, take a swipe or two at the Tree Sentinel, and then ride away before he can retaliate. This strategy only becomes more effective in his second phase, during which his area of effect attacks become especially hard to dodge.
Alternatively, you can fight the Tree Sentinel on foot. If you choose to do so, you'll need to learn his attack animations. He only has a few, and generally they can be dodged by rolling into his weapon at the right timing. (Shield attacks you'll want to roll away from.) Most halberd attacks can be punished with between one and two strikes. Try to stay on his weapon side, as his shield bash attack is very fast and hard to dodge.
If you want to be as careful as possible, hit him only once after each attack, and then roll away. This will make it almost impossible for him to punish your swing.
This caution is even more important in phase two, when his huge shield slam attack threatens to one-hit KO you at any moment. If he takes to the air, be sure to roll away as quickly as possible.
Ranged Strategy for the Tree Sentinel Fight
If you're attack from far away, this fight becomes much simpler. Just kite him from horseback, taking shots or firing off spells whenever you're within range but far enough away he can't respond. The only trick is not to cast spells into his shield when it's glowing, as he'll reflect your attack back at you.