Your Dexterity increases by 1 and either your Strength or Constitution score increases by 1.

Arvainians mature slightly faster than humans, reaching an age of adulthood at 16, and live longer, typically to about 120 - 140 years old.

Arvainians are typically chaotic. Other than that, their alignment can range anywhere from good to evil.

Arvainians are about the same size as humans ranging from just under 5 feet to around 6 and a half. Your size is Medium.

Your base walking speed is 30 feet, and you have a climbing speed of 30 feet

You can see in dim light within 30 feet of you as if it were bright light, and in darkness as if it were dim light. Your darkvision is different than most other races. You can only see in shades of violet.

You have 2 extra arms that can be used just like normal arms and can be hidden to blend in with normal humans.

As a bonus action, you can magically turn invisible until the start of your next turn or until you attack, make a damage roll, or force someone to make a saving throw.

    After you use this ability, you can't use it again until you complete a short or long rest.

You are able to recover from wounds with unnatural speed. As a bonus action, you may spend a Hit Dice to recover hit points.

     Twice per day, when you take a short rest, you can regain up to half of your expended Hit Dice rounded down.

You are vulnerable to acid and poison damage. If you take damage of either type, you may not use your regeneration trait to recover hit points until the end of your next turn.

Due to your odd physiology, you cannot gain the full benefit of any armor unless it has been specially modified to fit you, costing ½ of the armor’s base price.

    You can still gain the benefit of unmodified armor if you keep your extra arms inside it, limiting you to only two arms.

    If you do neither of those things you cannot gain the benefits of being proficient with any armor. (See Armor Proficiency in Chapter 5 of the Player's Handbook)

You can speak, read, and write Common and Arvainian.