I'm thinking of making a halfling rogue character and I was wondering whether or not scout is a good choice for a subclass. I've found several articles and videos about the scout subclass, half saying they're good and the other half saying they're the worst rogue subclass. I get that the effectiveness of each subclass varies based on the player's choices and what happens in the campaign, but I just want to know if scout in general is any good.

I've never played a Rogue, so maybe there's a synergy I'm not picking up on...but I'm not impressed. Looking at the class abilities:

Skirmisher gives you the ability to move upto your speed as a Reaction. It's an...interesting ability, but hardly one that gets me excited. They've already done the damage, this just let's you move without prompting an AoO. Kinda useful, if you don't use your Reaction for something else?

Survivalist gives you proficiency in Nature and Survival. Not very interesting.

Superior Mobility gives you an additional 10ft of speed. Meh.

Ambush Master gives you Advantage on Initiative. Twilight Clerics get that on L1, rarher rather than L13. It also gives you Advantage on attacks on a creature you've already hit in the first round. That could be useful for setting up Sneak Attack? If there is no Advantage or Disadvantage in play, and you haven't been able to set up Advantage another way. Could be good...but it is a bit weak for L13.

Sudden Strike allows you perform a second Attack as a Bonus Action, potentially allow a second use of Sneak Attack. This is a cool feature, although it does take until L17 to unlock.

There are some cool ideas here, but you'll be finishing most campaigns before the nice ones kick in. If you'll find it fun, great, but I'm not seeing it as particularly great in terms of power.

"Good" is subjective. If you will enjoy playing it, then it's fine. However, if you are concerned about mechanical value, it's pretty underwhelming, and it's abilities are easy to replace with magic items. Most campaigns don't reach level 13+, so if a subclass doesn't excite you pretty early on, you probably won't enjoy it much.

You should talk to your GM directly. If you end up dissatisfied, they can either modify the subclass to be more interesting, or compensate for it with in-game boons.

In the end, any class, or even a commoner NPC, can be fun to play if you take it in stride and have a good relationship with the other players. Find something "special" about your character to shine a spotlight on, and focus on filling a niche within your party.

The main reason to play a Scout is if you want to play a non-magical ranger character, because you get proficiency and expertise in Nature and Survival.

I like the Scout. If you want to focus on being a ranged damage dealer, their mobility lets you kite very well.

The rogue at my table chose scout specifically because of the survivalist, ranger-like theme. Our campaign has mostly taken place out in the wild as well, maximizing the subclass features. His PC doesn’t deal the most damage, but he still consistently racks up the most kills because the PC is still a rogue. Scout is pretty solid for what it is designed to be.

Quote from tslewis >>

I'm thinking of making a halfling rogue character and I was wondering whether or not scout is a good choice for a subclass. I've found several articles and videos about the scout subclass, half saying they're good and the other half saying they're the worst rogue subclass. I get that the effectiveness of each subclass varies based on the player's choices and what happens in the campaign, but I just want to know if scout in general is any good.

What about it and the campaign has gotten you excited? Why were you looking at the scout rogue in the first place?  Rogues are not front line fighters, as Sposta said it makes a decent wilderness archer/skirmishers but it’s not as versatile as a ranger if only because it lacks the spells. Personally I don’t think it’s as good a rogue as it. Gives up a lot of rogue to be spellless ranger. In the right campaign it can be an interesting character but I’ve never been overly impressed

The scout subclass seems to be made for a halfling character. The description says that scouts specialize in stealth and surviving in the wilderness, which works with halflings since stealth is one of their abilities. Also, the extra 10 move speed from scout's Superior Mobility trait brings their move speed from a below average 25 to an above average 35.

Quote from tslewis >>

The scout subclass seems to be made for a halfling character. The description says that scouts specialize in stealth and surviving in the wilderness, which works with halflings since stealth is one of their abilities. Also, the extra 10 move speed from scout's Superior Mobility trait brings their move speed from a below average 25 to an above average 35.

 
It also works well with the Wood Elf race. With Fleet of Foot stacking on top of Superior Mobility, the speed becomes a whopping 45 ft., for a Cunning Action Dash giving you a 90-foot threat range on top of your shortbow’s 80-foot threat range. Mask of the Wild dovetails nicely too.

Quote from Wi1dBi11 >>

Quote from tslewis >>

I'm thinking of making a halfling rogue character and I was wondering whether or not scout is a good choice for a subclass. I've found several articles and videos about the scout subclass, half saying they're good and the other half saying they're the worst rogue subclass. I get that the effectiveness of each subclass varies based on the player's choices and what happens in the campaign, but I just want to know if scout in general is any good.

What about it and the campaign has gotten you excited? Why were you looking at the scout rogue in the first place?  Rogues are not front line fighters, as Sposta said it makes a decent wilderness archer/skirmishers but it’s not as versatile as a ranger if only because it lacks the spells. Personally I don’t think it’s as good a rogue as it. Gives up a lot of rogue to be spellless ranger. In the right campaign it can be an interesting character but I’ve never been overly impressed

 What rogue parts is it giving up?

After giving it some more thought, I've decided to go with arcane trickster instead of scout. Scouts are only really effective in wilderness campaigns while arcane tricksters can be effective in any campaign.

Good luck with the arcane trickster they can be great fun.  In general rogue's are as good as what you want to get out of them.  With very little effort their sneak attack scales the entire game.  While that scaling is mostly linear its reliable.  Outside of getting off turn sneaks a generic rogue and an optimized rogue are extremely comparable in damage output.  

Scouts get a boost for damage primarily via their 13th level subclass ability.  Its a bit late to be much of an impact on play, but very good.

What scouts excel at is mobility and skills.  Picking up two additional skills WITH expertise puts them in a skill class ahead of most other rogues.  Skirmisher and superior mobility keep you from being pinned down in a fight and allow you to move about the battlefield for optimum positioning.  

The best part about scouts (and rogues in general) is that many of their features don't use resources that refresh on a short long rest.  They are always on.  While the rest of the party can start to feel the squeeze of a long adventuring day as they lose slots/battle master dice/ki/etc rogues just keep going handing out sneak attacks every round.The arcane trickster is the exception to this and can be difficult to work with managing limited slots.

Quote from tslewis >>

After giving it some more thought, I've decided to go with arcane trickster instead of scout. Scouts are only really effective in wilderness campaigns while arcane tricksters can be effective in any campaign.

I would disagree with this. There is only one subclass feature that is geared toward wilderness and that is survivalist, which is the second 3rd level feature. Skirmisher is amazing when melee close in on you and you have a ranged weapon no matter what environment you are in. Superior mobility is 10ft, or 20ft with a bonus action and this has synergy with skirmisher. Ambush master gives you an almost guaranteed first or second spot on the initiative order and you give everyone else advantage on attacks against that creature until the start of your next turn. Since you went first or nearly first, this is fantastic. Finally, there is sudden strike, which has synergy with ambush master or you can get a second sneak attack on a different target. A second sneak attack. I feel that a player has to basically try to screw this build up to make it not effective.

Scouts are rogues which means that they'll never be bad. As for when they are best, well, that depends on your table and how your GM handles things. Can you use Survival to track someone through a bustling city? Perfect, you have expertise in that! Do you want to play as a kind of quick-draw duelist? Well, just grab the crossbow expert feat and you can. Want to play as a skill monkey? Well, you just got two free proficiencies AND expertise.

Scout is also a great basis for many good multiclassing options. Combine with fighter and you have a non-magical Ranger, if that's your thing. Want to be an almost OP assassin? Throw in five levels of Gloom Stalker and no-one will see you coming.

All in all, it's very much what you make of it. To answer your question, yes it is "good". But is it fun and right for YOU to play? That's up to you. Arcane Trickster is known as one of the most versatile and popular rogue subclasses, so you probably can't go wrong there. :)

Our little long term gamer group have always called Scout "the better ranger".

Scouts are the best skill monkeys in the game IMO.   I recently played one and it was pretty awesome.  I think the subclassis awesome, especially in a game that is balanced between 3 pillars and includes a  wilderness component.  

To really maximize this I like to get a background with cartographers tools proficiency and I would play a PHB half-elf.  On Point buy you can start with17 Dex and two 14s and a 12 in Wisdom, Charisma and intelligence while still sporting a 10 con.  Pick up skill expert and bump Dex to 18 and at 6th level you have 11 skill proficiencies and expertise in 7  of them.   I like expertise in Deception and Athletics to start, Nature and Survival with the subclass and expertise in Stealth, Perception and Investigation picked up later with the class and feat.

If your game is inside a dungeon it will still be great as long as all 3 pillars are played equally. If your game is hack and slash there are better choices (and to be honest better classes).

The only real problem I ran into playing this is I was hands down the best at most out of combat things we had to do.  I outsurvivaled the Ranger and Barbarian by a wide margin, I outalked the Warlock most of the time and my athletics was on par with the Paladin despite an 8 strength (better than him late in game when I got gauntlets of ogre power).  This created a little bit of controversy early in the game when I was "the guy" out of combat, but I reminded them that they were all substantially better than me in combat. 

Fast forward to 2024 and the scout rogue is still very good. I created a multi-class scout rogue / gloom stalker ranger. The built-in nature and survival proficiencies mean that I can choose additional skills without trading off. For reactions, there are multiple choices for various situations: Skirmisher when enemy ends turn without hitting you. Uncanny dodge for mitigation when an enemy attack is successful.