Assassin Rogue Guide

You have advantage on attack rolls against any creature that hasn't taken a turn in combat yet. In addition, any hit you score against a surprised creature is a critical hit.

You gain proficiency with the disguise kit and the poisoner's kit.

You can unfailingly create false identities for yourself. You must spend seven days and 25 gp to establish the history, profession, and affiliations for an identity. You can't establish an identity that belongs to someone else. Thereafter, if you adopt the new identity as a disguise, other creatures believe you to be that person until given an obvious reason not to.

You can apply a special poison to your weapons as a bonus action. The next time you hit a creature with a weapon attack within the next minute, the target takes additional poison damage equal to your Sneak Attack damage and must make a Constitution saving throw (DC 8 + your Dexterity modifier + your proficiency bonus) or be poisoned for 1 minute.

When you hit a surprised creature, it must make a Constitution saving throw (DC 8 + your Dexterity modifier + your proficiency bonus). On a failed save, the damage of the attack is doubled.