As I mentioned in my previous post, I've been thinking about how to build an Investigator rogue. Since I woke up ridiculously early this morning and couldn't get back to sleep, I now have an initial draft of the Investigator archetype to share. The goal of this archetype is to model both Sherlock Holmes and Philip Marlowe without going too far in leaving the medieval fantasy behind. Yes, I know that the modern conception of the detective comes from 1833, with a guy who has Rogues Are My Jam written all over him, but if this kind of detail is enough to ruin your fun, then move along, friend. If it's good enough for Pratchett's medievalish fantasy, it's good enough for me. Also, my closing argument.
Where others use the talents and training of a rogue for personal gain, you turn those same abilities to investigating mysteries. You may not be above working both sides of the law, but when there are people in need or tantalizing mysteries to uncover, you can't help yourself. You might be the sort who only cares about the puzzle and proving your intellectual superiority, or you might be driven to enact rough justice.
Beginning at 3rd level, whenever you begin an investigation into a crime or other mystery, gain a temporary Bond with whatever has drawn you into the investigation - perhaps the death of an ally, or your interest in a femme fatale. This Bond lasts until you conclude the investigation. If you take on a second investigation without concluding the first, rewrite the Bond of the earlier investigation(s) as a Flaw, as you are tormented by your cold cases.
You can size up an opponent and spot some weaknesses. While you have your opponent within line of sight, roll Wisdom (Insight) or Intelligence (Investigation) against DC 15 as an action. If the opponent is aware of your observation, it may oppose your roll with Charisma (Deception). If you succeed, you create a Hunter's Mark effect upon the opponent. This effect does not require Concentration, spell components, or any obvious spellcasting effort. You must take a short or long rest before using this ability again, or expend Inspiration.
At 3rd level, choose one of the abilities below.
Savant: Gain proficiency in two of the following: Arcana, History, Investigation, Medicine, Nature, Religion, any item on the Tools list, or any language. Double your proficiency bonus with one of the skills or tools you choose.
Further, once per month, you may attempt an Intelligence (Investigation) check against any investigation that has become a cold case, as you remember something you overlooked or put together something that has eluded you. The DC for this ability check is typically 20 or 25.
Hard-Boiled: Whenever an enemy reduces to you 0 hit points, you gain advantage on death saving throws, and gain Inspiration when you recover (gain 1 or more hit points). If the enemy is directly part of your Ideal, Bond, or Flaw, you gain temporary hit points equal to 1d8 + your character level when you recover. These temporary hit points last until used. You may not gain Inspiration or temporary hit points from this ability more than once per short rest.
By 9th level, you have kept extensive notes on your past cases. Drawing on this well of knowledge, you can:
Use your rogue level in place of your ability score bonus and proficiency bonus on any ability check made as part of a Research action. You do not incur the normal 1 gp additional expenses from the Research action.
Whenever you encounter a character you have been in conflict with before, you may make a Wisdom (Insight) roll against DC 15. On a success, you learn one of the target's Bonds, Ideals, or Flaws. You must be aware that the character is the same person you have previously encountered (that is, this ability does not automatically pierce disguises).
Whenever you encounter a type of creature you have previously encountered (and you have taken at least a short rest since the initial encounter), you may make an Intelligence (Investigation) roll against a DC equal to 5 + the creature's CR. On a success, you learn one of the following: the creature's damage immunities, damage resistances, condition immunities, damage vulnerabilities, or one special trait. You decide which of these you are attempting to learn after you roll.
Starting at 13th level, you gain advantage on all saving throws against illusions, and on Intelligence checks to escape the maze spell.
At 17th Level, choose one of the abilities below.
Triumph of Reason: This ability is identical to the cleric ability in the Knowledge domain, Visions of the Past, except that you use Intelligence rather than Wisdom, and the ability is not magical in nature when you use it. (Not reprinted here, as it might stretch the bounds of fair use.)
Agent of Justice: You lash out against the corruption all around you - in the law, in society, even in the forces of the cosmos. You become an agent of justice, fighting with a burning ferocity. While in a fury, you gain the following benefits:
You have advantage on Dexterity checks and Dexterity saving throws.
Your weapon attacks score a critical hit on a natural 19 or 20.
You have resistance to all damage types.
Your movement speed increases by 10 feet.
Your fury lasts for one minute. It ends early if you are knocked unconscious, or if you end a turn without having attacked an enemy or taken damage since the end of your previous turn. You may end your fury on your turn as a bonus action. After you use this ability, you must take a long rest before you can use it again. You may use it one additional time per long rest by expending Inspiration.
In many campaigns, Hard-Boiled Detective and Agent of Justice are obviously better, because they offer combat functionality. To be fair, a two-fisted noir private eye would be more useful in a monster-thumping game than Sherlock Holmes would. All I can really say to that is to know your DM and what kind of campaign you're getting into; DMs, advise your players accordingly. If you're not interested in creating mysteries to investigate, the hard-boiled detective should still work well and be fun.
I'm doing some weird stuff with Bonds, Flaws, and Inspiration here, because why and how much the detective cares about the case make a difference in the protagonist's success - particularly in pushing past the Act IV reversal. It's not for every table, and for that matter I am not sure how well it will work in actual play if not every adventure is an investigation. I tried to make it a bonus thing rather than the whole of an ability.
It's possible that Case Files is too complicated or too obscure in its application for the position it holds in the rogue's progression. I dunno. 5e lives and dies by simplicity in clarity and function - it's harder than it looks.
Ending a rogue archetype with a barbarian rage parallel is kind of an odd choice, but I was thinking of characters like Sam Vimes and Batman who show a deep well of anger that sees them through danger, but must be restrained at the last moment to avoid violating the protagonist's all-important ethos.
This archetype is part of an ongoing series of posts playing with ideas around procedural investigations and characters on both sides of the law. See also Investigation Encounters, the Enforcer Background (good for touching on these themes while playing other classes), and the Mastermind Archetype (the parallel between Case Files and The Mastermind's Library, each at 9th level, is not an accident - this archetype is here to be your nemesis). The Investigator, like the Mastermind, is built around encouraging rogues to make Int their second-highest score... or first, maybe. If I were to change anything about the themes of the Investigator archetype, I would make them better team players (sort of like the Mastermind), but every detective story is about an individual or duo, rather than a larger team or organization. (Even detective stories focused on the NYPD mostly treat cops outside the duo as hurdles than useful allies.)
Finally, I'd like to thank Kainenchen and Stands-in-Fire for their invaluable contributions to this post.