it seems that wizards should work really well in the rest variant where a short rest takes 8 hours and a long rest takes 7 days for multiple reasons:

- arcane recovery has a limit "per day" and not "per long rest", so it can be used to recover a small amount of your spell slot capacity each short rest

- your version of ritual casting is slightly stronger than it is for other spellcasting classes since you can cast any ritual spell in your spell book

- you have a built-in way to spend all the downtime you get during long rests since you can use that time to copy any spells you find, and a lot of wizard spells require long term investments to function at their fullest (particularly ones that let you create permanent things like teleportation circle, mighty fortress, guards and wards, forbiddance, galder's tower etc work best in a slower campaign pace)

- all the wizard subclasses in the player's handbook and also the war wizard work really well in this kind of campaign as all of them rely on either at-will features, passive features, things you can do per short or long rest or things that recharge whenever you cast a spell of a certain school (including when cast as a ritual). The only collage that falls behind a little is enchantment, where you get features that recharge per long rest per victim, where you will have to diversify your targets

is the wizard outshun by the warlocks, monks, fighters and rogues in this type of rest variant? maybe, but it is still a really excellent class choice in that very specific type of campaign

I’m playing a Gritty Realism one-shot campaign right now and resourceless classes are much more reliable - Champion Fighter and Rogue. Our Monk is doing good as well because we are taking some short-rests once in a while.

Our Paladin and other full casters are super worried to burn resources for nothing and they are suffering a little bit.

I actually agree with you. My table has been using the gritty realism rest rules and enforcing missile counts, weight and such for the past 3 years across 4 campaigns and ive played a wizard in 2 of them and I love it. I have played a human both times for the initial feat and taken magical initiate both times for prestidigitation and mage hand plus a daily use of mage armor. Cantrips are the bulk of my damage dealing, so much so that until level 5 I dont take any additional damaging spells. Id rather save those resources for control and buff/debuffs that have a greater effect. I do suggest if you are playing a long campaign with these rules be an evocation wizard. Potent cantrip is a huge deal in being able to always deal some cantrip damage. beyond that yeah arcane recovery is a huge boon. It also has a kind of older school feel for the wizard too in that spell scrolls, wands and such are a much bigger tool for the wizard than they are normally in 5e.

Eh... I don't know. My wizard is in a gritty realism campaign right now and she spends almost all combats just spamming Firebolt because spell slots are so precious, especially with spells like Mage Armor which are specifically made for day-long periods between long rests. I didn't realize that Arcane Recovery recharges every day though - I'll have to remind the DM about that. I also think that there should be an exception to the long rest rule for prep casters, so they can switch out spells during short rests as long as they spend enough time doing so. (My DM has already approved this change but I don't know about other DMs.)

Wizards do seem to be the best casters for gritty realism, but I agree with Ir0ns0ul that non-caster classes are way better off.

The one change we made to the Gritty realism rules is that racial abilities, feats, magic items and some class features that all reset on a long rest instead reset daily. Things like Rage, and the such. General class abilities that arent subclass dependent. This allowed the wizard I play to be a V-Human and take magical initiate as the initial feat and it gets me a daily pop of mage armor without wasting slots. I did find myself writing and buying LOTS of spell scrolls to supplement my casting in the field. There is something to be said about spell slots being a very very valuable resource that are treasured. For wizards I think it plays into the over all theme of the an ultimate planner/swiss-army knife which the wizard excels at. Plus if you have large period of played downtime its easy for a wizards and other casters to make money with spell casting services and make those spell slots a value money making commodity. 

Okay, here is one potential problem with allowing wizards to use arcane recovery every day while using gritty realism.

From the DMG:

Limited Usage

Some special abilities have restrictions on the number of times they can be used.

X/Day. The notation “X/Day” means a special ability can be used X number of times and that a monster must finish a long rest to regain expended uses. For example, “1/Day” means a special ability can be used once and that the monster must finish a long rest to use it again.

My guess is that there wasn't any intent to differentiate between "per long rest" and "per day" and that in practice the writers used them more or less interchangeably.  I highly doubt that it was intended for there to be any actual difference between Arcane Recovery and the Land Druid's Natural Recovery which uses the "once per long rest" phrasing but is otherwise identical to arcane recovery. 

As a DM, I would be inclined to not allow arcane recovery to be used every day if the adventure involved multiple days of travelling or whatever and I was counting on gritty realism to not have my casters go into every encounter with full resources.    

As a DM thats your prerogative. I would say though that there have been errata's and retcons of specific wording of things over the years to better clarify the intent and that until arcane recovery is officially changed in an errata or commented directly on by someone like Jeremy Crawford that it does work per day not long rest. 

But according to the DMG, you must complete a long rest for something that recharges once per day to be regained.  We'll have to agree to disagree.

Well actually we do agree, I was just wrong in the beginning. Jeremy Crawford clarified it in a tweet back in 2016 that arcane recovery does indeed require a long rest to rest.

https://twitter.com/jeremyecrawford/status/739191296334520320?lang=en

Whoops. Well, I guess I’m not bringing that up with my DM after all!

I’m still curious about how to make cantrip spamming interesting. I’ll eventually be controlling summon spells (conjuration for the win!) but until then I need to find some way to not get tired of Firebolting everything that attacks us.

Quote from Zoltar99 >>

Okay, here is one potential problem with allowing wizards to use arcane recovery every day while using gritty realism.

From the DMG:

Limited Usage

Some special abilities have restrictions on the number of times they can be used.

X/Day. The notation “X/Day” means a special ability can be used X number of times and that a monster must finish a long rest to regain expended uses. For example, “1/Day” means a special ability can be used once and that the monster must finish a long rest to use it again.

 

My guess is that there wasn't any intent to differentiate between "per long rest" and "per day" and that in practice the writers used them more or less interchangeably.  I highly doubt that it was intended for there to be any actual difference between Arcane Recovery and the Land Druid's Natural Recovery which uses the "once per long rest" phrasing but is otherwise identical to arcane recovery. 

As a DM, I would be inclined to not allow arcane recovery to be used every day if the adventure involved multiple days of travelling or whatever and I was counting on gritty realism to not have my casters go into every encounter with full resources.    

Quote from Zoltar99>>

But according to the DMG, you must complete a long rest for something that recharges once per day to be regained.  We'll have to agree to disagree. '

intent is one thing, pretty obious that the original intent was for it to work per long rest anyways, but it is a bit curious that this wording has not been altered in the erratra since 2016, they know that the wording might cause confusion, and yet they did not fix it the same way they reworded many other abillities to be clearer.

(also the specific excerpt is from the monster manual, not the DMG, and refers to how to read monster stat blocks, information about PC's and their abillities is not supposed to be found in such a source. Plus the way it is denoted is slightly different from how it would be in a monster stat block)

point is that RAW, it works once per day, not once per long rest. When the text says that something is once per day then it is indeed usable once per day,. If you have to follow RAW slavishly or if you find it reasonable for an abillity to now be usable 7 times more than normal (and that is a far more complex question, if you are trying to go for the same number of encounters per long rest and the same number of short rests per long rest that the game would normally be built on but simply with longer time periods then the answer would be no, if you on the other hand are still going to have adventuring parties that are active in combat day-to-day and you also allow warlock to mess about it might be reasonable? Depends on the game and the story and the DM and all that jazz obviously)