Cunning Action. On each of its turns, the thief can use a bonus action to take the Dash, Disengage, or Hide action. Evasion. If the thief is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the thief instead takes no damage if it succeeds on the saving throw and only half damage if it fails. Sneak Attack (1/Turn). The thief deals an extra 14 (4d6) 4d6 damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the thief that isn't incapacitated and the thief doesn't have disadvantage on the attack roll.
Multiattack. The thief makes three attacks with its shortsword. Shortsword Melee Weapon Attack: +7 to hit, reach 5ft., one target. Hit: 7 (1d6 + 4) 1d6+4 piercing damage. Light Crossbow. Ranged Weapon Attack: +7 to hit, range 80/320ft., one target. Hit: 8 (1d8 + 4) 1d8+4 piercing damage.
Uncanny Dodge. The thief halves the damage that it takes from an attack that hits it. The thief must be able to see the attacker.
Master thieves are known for perpetrating daring heists. They tend to develop a reputation and a cult personality. A master thief might "retire" from hands-on work to run a thieves' guild, spearhead some covert enterprise, or enjoy a quiet life of luxury.