1 - Death Mark
You learn the Hunter's Mark spell and can cast it at will without expending a spell slot. While a creature is marked, weapon and poison damage attack rolls made by you and your allies deal the spell's damage as poison damage. This extra damage increases by 1d6 per tier of play.
1 - Skirmisher's Stride
You gain proficiency in the Acrobatics skill.
While you are not wearing heavy armor, opportunity attacks against you are made with disadvantage.
1 - Skulker Subclass
You gain a Skulker subclass of your choice. For the rest of your career, you gain each of your subclass’s features that are of your Skulker level or lower.
2 - Bait and Switch
As a bonus action, you can switch places with an ally within 5 feet of you. This movement does not provoke opportunity attacks. When you do so, your ally can use their reaction to make a weapon attack against a creature within 5 feet of your original position.
You can use this bonus action a number of times equal to your Dexterity modifier (minimum of once), and you regain all expended uses when you finish a long rest.
2 - Coordinated Strike
When an ally within 5 feet makes an attack roll, you can use your reaction to grant the attack roll a bonus equal to your proficiency bonus.
4 - Ability Score Improvement
You gain the Ability Score Improvement feat (or another feat) at Skulker levels 8, 12, and 16.
5 - Gambit
When you make a weapon attack, you can choose to reduce your attack roll by up to 5. For each point reduced, add +2 to the attack’s damage roll.
6 - Heightened Awareness
Your heightened awareness allows you to notice details others miss. You gain proficiency in the Investigation skill. Additionally, when you make an Intelligence (Investigation) check, you can treat a roll of 7 or lower as an 8.
7 - Noxious Diversion
As an action, you can throw a vial up to 15 feet that shatters in a 10-foot radius, releasing a cloud of smoke and toxins. Each creature in the area must succeed on a Constitution saving throw (DC = 8 + your proficiency bonus + your Intelligence modifier) or become blinded and poisoned for 1 minute. Affected creatures can repeat the saving throw at the start of each turn to end the effect.
9 - Poison Expertise
When dealing poison damage, you ignore resistance, and treat immunity to poison damage as resistance instead. Additionally, your poison damage rolls deal an extra damage die.
11 - Silent Negotiator
You can add your Dexterity modifier (minimum of 1) to Charisma (Persuasion) and Charisma (Intimidation) checks without speaking, allowing you to negotiate quietly.
13 - Hex Mark
When you hit a creature with a melee attack, that creature has disadvantage on saving throws against spells and poison effects until the start of your next turn.
15 - Toxic Knowledge
You can use an action to identify whether a food, drink, or object is poisoned without any equipment. In addition, you gain resistance to poison damage and advantage on saving throws against being poisoned.
16 - Healing Fumes
When you or an ally makes a melee attack against a creature affected by a poison that deals damage, you can use your reaction to regain hit points equal to the poison's damage die plus your Intelligence modifier.
You can use this bonus action a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a short or long rest.
18 - Mortal Reminder
Once per turn, when you have advantage on an attack roll, you deal an extra 3d6 damage to the target. If the target is frightened, poisoned, or under another negative condition, the extra damage increases to 5d6.
20 - Expert of Toxins
Whenever a creature is affected by any poison damage effect, it takes the poison damage at the start of its turn, at the start of your turn, and whenever you hit it with an attack until the poison wears off.
