I'll preface this quickly by saying I've been playing D&D for well over 15 years on both sides of the screen. Fifth Edition is definitely one of the smoothest rulesets of Dungeons & Dragons, but it's not without its wrinkles. I can see that Larian wants to make some changes and bring some of the weaker classes up to parity with the stronger ones (what with the ranger changes) and so I figure now is as good a time as any to offer some of the minor (and major) changes I apply to my own games to make things seem more fair as well as more engaging.
This handful of custom rules are mostly implemented to balance the game out, as well as enrich the strategic depth of the game (especially for martial classes). The changes fall into 2 categories:
Global Changes (i.e. balance changes that apply to everyone)
Class Specific Changes.
Don't worry, it's actually a very small list.
Global Changes:1. Bows are a finesse weapon - in terms of how real life bows actually operate and the levels of draw strength required to wield certain compound bows, it is not only more realistic that a bow be able to gain bonuses from strength (more draw strength means the arrow travels faster, farther, and penetrates armor better) it also gives strength characters better options for long range weaponry, as the current "free object interaction" rules for drawing weapons and the limited range of throwing weapons, makes them less than ideal. In a game that focuses so much on "verticality", opening up ranged options for all characters will be important. Dexterity is often considered a superior offensive stat in 5e, as it contributes to many great skills as well as initiative, AC (in some cases) and now melee and ranged weapon attack bonuses. Even with the utility we see being lumped onto shove as a bonus action, if only one change was to go through from all of this, this is the one. It makes sense for realism and it improves the balance of the game.
2. The Extra Attack class feature also opens up disarm, trip and pushing attack maneuvers as free additions to one melee weapon attack on the character's turn (without bonus damage dice) - I've played my fair share of martial characters and they really do struggle for tactical ways to contribute to a combat. This gives them neat ways to control the battlefield and I can see that Larian are already trying to do something close to this by making shove a bonus action. Casters already have cantrips that carry far stronger debuffs, so this does little to break the game, and again, brings melee characters a little bit more up to par.
3. Critical Strikes deal maximum damage instead of adding bonus dice. Features that add bonus dice to critical strikes (like a barbarian's brutal critical) are still rolled. - I mostly just see the concept of dishing out a critical strike that rolls badly and ends up dealing less damage than a normal hit as being both anticlimactic and not so great for emersion and imagery. "You critical strike the monster in the eye for....6 damage!" It should be noted that in cases of large dice rolls this will improve consistency of critical damage but actually REDUCE the average damage of critical strikes (especially those with many dice) -but!- also reduces the chances of players being crit to death with high damage rolls from monsters.
So yeah...3 global changes. If anything these are the ones I find to be most important.
Class changes:The class specific changes are also something I see you've been embracing Larian (like thief rogues and rangers). I have my own set of changes that really smooth out some of the weaker classes.
Please note that the following classes received no changes: Artificers, Bards, Clerics, Druids, Paladins and Wizards (they're good enough!)
Some of these changes aren’t relevant to the level ranges of Baldur’s Gate 3 but I am putting them down anyway so that Larian has some food for thought if Baldur's Gate 4 is going to be a thing (and maybe you 5e players out there can get some good ideas too!)
It should also be noted that I have play tested all of these changes with groups of live people and they all have enjoyed the changes.
Barbarians: Brutal Critical now improves critical strike range in higher levels. (This is one of those examples of a change that doesn't apply to current level ranges for Baldur’s Gate 3) at level 13 the Barbarian doesn't receive more bonus critical strike weapon damage but instead improves their critical strike range to rolls of 19-20 and at level 17 they gain an additional weapon dice and improved critical range of 18-20. Big crits are what barbarians are all about and this lets them get those moments more often as well as preventing their damage from falling behind in higher tiers of play.
Frenzied Berserker: The bonus action used to enter a frenzy can be used to make a melee weapon attack as well. As much as people hate the exhaustion, the deal breaker for me is that the first round you enter your rage you don't even get the extra attack from frenzy and still incur exhaustion. Most combats are over in 3-5 rounds so this is actually a big deal. (Some people want to do away with the exhaustion altogether but not me).
Fighters: Extra Attack (3) is gained at level 17 and their new capstone at level 20 is that they regain the use of all expended short rest features from the fighter class when initiative is rolled. I don't like how Warlocks are getting their 4th beam at 17 and Fighters are still waiting 3 more levels to get that extra attack. It's a minor change but an important one.
Arcane Archers: Get a number of special shots equal to their proficiency bonus that recharge on a short rest (instead of 2....)
Monks: (Probably the most extreme overhaul) Ki now regenerates fully at the end of the Monk's turn and they get 1 Ki per Tier. (meaning 1 Ki at levels 1-4, 2 Ki at levels 5-10 etc). Why? Because Short rests are very annoying and Monks have remarkably little longevity in long encounters especially in tiers 1 and 2. This also necessitates that Way of the Four Elements Monks have their costs be reduced to be equal to the level of the spell (or in the case of cone of cold reduced to 4).
At level 6 when a monks unarmed attacks count as magical for the sake of overcoming damage reduction they also gain a bonus to their hit and damage with unarmed attacks equivalent to any magical weapon they are wielding. Unarmed attacks are the bread and butter of monks and if you get magical gear, using your unarmed attacks shouldn't feel like a penalty.
At level 11 using flurry of blows no longer costs Ki.
At level 20 using flurry of blows no longer costs a bonus action. (meaning if can also be done as part of an opportunity attack :D)
Rangers: Larian clearly has their own ideas here. I've found that the Ranger functions best as a fighter subclass, much like the eldritch knight but with Druid spells (no school limitations) and instead of cantrips, gets expertise. Later they get bonus action stealth and enhanced senses and attacking from hidden. etc. If prompted to, I will leave details in the comments.
Rogues: At level 5 receive Crippling Strike: When the rogue lands a sneak attack from an attack made with advantage, the rogue chooses one of the following effects: The target has their movement speed reduced by half, disadvantage on their next attack, or disadvantage on their next saving throw against a spell unless they make a strength, dexterity or constitution saving throw, respectively. The DC is equal to 8 + proficiency bonus + dexterity modifier of the rogue. EDIT: This effect lasts until the start of the Rogue's next turn.
The idea is to give rogues options if they are able to get advantage on their attacks instead of just doing the same thing over and over they have a means to contribute tactically.
Assassin: No longer requires surprise to guarantee a critical strike (since they must also beat them in initiative to do so) but must be hidden from their target when combat begins and guarantee the critical for only the first attack they make in the combat if it hits. I just think that the current Assassin feature requires too many things to go right. They need to get surprise, they need to win initiative AND they need to land an attack. This removes -one- of those requirements.
Sorcerers: Receive +1 Spell known per tier of play (so 3 spells known at level 1, 7 spells known at level 5, 15 spells known at level 11 etc.) and can swap one spell known for another of the same level once per long rest. Being locked into a crappy spell list really hurts sorcerers as they rely so heavily on their spell list, and they frankly, have too few spells known.
Warlocks: At level 5 Warlocks receive +1 spell slots but still only recover the normal amount they would have recovered. Meaning a level 5 warlock would have 3 spell slots but would still only recover 2 from a short rest, a level 11 Warlock would have 4 spell slots but still only recovers 3 etc. 2 spell slots is ridiculously limiting. It should expand to 3 so that in big fights a Warlock can still step on the gas a bit, but still only recover what they normally would from a short rest. Considering 5e was balanced around 2 short rests a day and Larian has opted for 1 I think this change is ideal.
Anyway, as you can see -most- of the changes are quite minor. I’m sure many of you have lots to say about these changes, whether it be good or bad so have at it

(I will probably include some edits for formatting)