Rogues who prefer to wait for the right moment, and exploit the right opening find themselves along the path of an ambusher. An ambusher believes that the best fight is one that happens when and where you want.
Free Motion Level: 3
When you choose this archetype at 3rd level, you are able to travel anywhere you could possibly find yourself. You gain the ability to climb and swim faster than normal; climbing and swimming no longer cost you extra movement.
Higher Ground Level: 3
Starting at 3rd level, you have a natural inclination towards heights, and specifically, heights above others. You don’t need advantage on your attack
roll to use your Sneak Attack if your target is 10 feet or more below you. All the other rules for the Sneak Attack class feature still apply to you.
Slippery Level: 9
Beginning at 9th level, whenever you take the disengage action you can freely move through any other creatures space without becoming impeded. In addition, you have advantage on saving throws against effects that would grapple or restrain you.
Lingering Observer Level: 13
Starting at 13th level, you are able to gain knowledge or information from just being able to observe another creatures actions. If you are able to see a creatures mouth moving you can understand what they are saying as long as you are capable of understanding the language being spoken.
In addition, if you spend 1 minute or more observing a creature and doing nothing else, you gain knowledge of the creatures behavior and situational awareness. That creature has disadvantage on Wisdom (Perception) checks to contest your Dexterity (Stealth) checks as you know how to best hide from its view.
Seize the Moment Level: 17
When you reach 17th level, you can identify an opportunity when you see one. On your turn you can choose to take advantage of the current battle state and seize the moment. If you choose to seize the moment you gain a second action that you can take this turn that can be used only for the Attack action. In addition to this, you are limited to using Sneak Attack twice, instead of once, on this turn.
Once you use this feature, you can’t use it again until you finish a short or long rest.