Inspired by the observational prowess of Sir Arthur Conan Doyle's Sherlock Holmes.

You excel at taking in the details of the world and applying that information to a highly rigorous categorical system to maximize your effectiveness in the field. Working first with raw talent that allows you to identify abnormalities quickly. You soon start to be able to take advantage of your enemies movements through a consistent study of behavior and motion. As you systematically build on those skills you become able to move the battlefield to your advantage by anticipating your enemies actions.

As an observational expert you gain the cantrip Guidance. You gain access to the Zone of Truth

No one likes a know it all... you're charisma will be penalized as your observational prowess increases.  

Science of Deduction

Your observational skills and categorical imperative allow you to assist your allies and stay one step ahead of your enemies. 

At Level 7 you have the ability to use Slow once per day. 

At Level 11 you have the ability to use True Seeing once per day.

At Level 16 you have the ability to use Time Stop once per day. 

There is no material expenditure for these spells.

Broad Scan

At 3rd level, you gain one of the following features of your choice.

Battlefield Watch

As an action the Ranger marks all enemies that fail a Stealth save with a negative two modifier. All targets that fail the save are marked for one hour, or until they are out of the range of sight of the Ranger for more than one turn, whichever is first. Marked targets stealth at a disadvantage.

Inspection

Your experience in looking over parade inspections of troops allows you to quickly identify a loose strap or kink in your allies armor. Each day, as an action there is a chance that you will be able to increase the Armor Class of each of your companions who wear armor until their next long rest.

Sillouette Recognition

Scanning a room quickly reveals the shapes and silhouettes of items that are out of place giving the Ranger a bonus to detection of hidden items and to hiding characters.

Focused Observations

At 7th level, you gain one of the following features of your choice.

An Eye for Faint Movement

You see the slight movements preceding an attack and react accordingly. You're ear picks up the sound of a tightening bowstring from across the battlefield.

The first physical attack against you in each turn is made at a disadvantage.

Quick Size Up

Your experience in battle has made it possible for you to identify poorly donned or overly worn areas of a targets armor, and you've learned to compensate for the stance of your adversary. You make armed physical attacks against enemies wearing armor with a bonus to hit.

Minute Observations

At 11th level, your previous choices determine a new ability.

Those that have chosen "An Eye for Faint Movement" will benefit from "Focused Target"

Those that have chosen "Quick Size Up" will learn "Armor Best Practices"

Armor Best Practices

You permanently gain {{modifier:AC+1}} while wearing armor.

Focused Target

You can activate the True Strike cantrip as a bonus action up to three times. This ability is reset after long rest.

Otherworldly Omnicience

Your ability to infer danger from minute observations allows you to anticipate your enemy, sometimes years in advance. You've cozied up to, bribed, influenced, or stolen from just the right people to put them into just the right place at just the right time to create a "butterfly effect" to bring you just what you need at this time and place. After describing your antics to your fellow adventurers and how all of these small acts fell into place to create this opportune situation; a wish is granted.

Due to the time required to prepare this situation you are only ever able to use this ability three times.