Limbing

At 11th level, you gain the ability to grow an extra limb, or regrow lost limbs. The extra limb normally grows from the center of your chest, and functions as an ordinary arm.

To attempt to grow an additional limb you must completely submerge yourself in a pile of leaves, branches, and earth, and enter a hibernative state for 8 hours. If you are prematurely roused during this period the limbing fails and you are drowsy and disoriented for 1 hour, having disadvantage on all attack rolls and ability checks.

If the 8 hours passes undisturbed you emerge with your new limb. If you were replacing a lost or severed limb the replacement functions exactly as the original did. If you were growing an extra limb you have gained an additional arm, which can wield weapons, shields and other objects exactly as your other arms do.

A greenwood ranger with 3 arms may attempt a special variation of the normal two weapon fighting rules. When you take the attack action and attack with a weapon with the Light property used in one hand, you may use a bonus action to attack twice, as long as each attack is made with a different light weapon held in a different hand, but without adding your ability modifer to damage for these attacks. Any fighting styles or feats that alter normal two weapon fighting affect this special variant in the same way (so the two weapon fighting Fighting style allows you to add your ability modifier to each additional attack, and the Dual Wielder feat removes the restriction of being Light from all of the weapons)