I have a friend who's interested in D&D and is coming from a background in 40k and Star Wars Armada. Given the difference in types of games, I worry about them being bogged down and overwhelmed. Truth be told, I get the sense that Artificer stands out to them because it's the closest approximation to a flamer Space Marine.
Is the D&D 5e Artificer friendly to new players?
The Artificer is one of the most complex classes available. They have two features in particular that have an exceptionally large list of options.
Infuse Item:
At 2nd level, you gain the ability to imbue mundane items with certain magical infusions. The magic items you create with this feature are effectively prototypes of permanent items.
This comes with something like 16 infusion options. Additionally one of these infusions is called “Replicate Magic Item”:
Using this infusion, you replicate a particular magic item. You can learn this infusion multiple times; each time you do so, choose a magic item that you can make with it, picking from the Replicable Items tables. A table’s title tells you the level you must be in the class to choose an item from the table. Alternatively, you can choose the magic item from among the common magic items in the game, not including potions or scrolls.
The list of magic items has 48 items to choose from.
As a newbie, one lacks the experience that makes choosing between all these options easy. Without some experience playing the game, it’s probably impossible to know what infusion or magic item choices make sense and will be fun at any given time.
Additionally, the subclasses are fairly complex combat wise. They create a lot of additional rules for using them in combat on top of the usual rules for combat. If I’m a fighter with a sword, my class features are pretty simple, and I can figure out what I’m doing if I’ve got a grasp of the basic combat rules. With the artificer, you need a good grasp of the basic combat rules to even begin to make sense of the combat based subclass features available to each subclass.
And the artificer has spellcasting on top of all of this.
Overall, the artificer is a very complicated class, and it will likely be difficult to play without already having a good grasp of the basic rules. Some of the complexity is mitigated by not having all of those options available at earlier levels, but in my experience, it is still significantly more complex than most classes, even in Tier 1 play.
I was in a similar situation, wanting to play an artificer but not knowing if it would be too hard, as someone who has played barely any 5e. Complexity-wise, I would place it as being harder than playing most martial builds, but less complicated than many full spell casters. But — with the right supports — it definitely is manageable, even with little to no DnD experience. And it's more fun than playing something you're not passionate about.
Your friend has a character concept already and that makes some choices for them. When I built my character, I didn't have a concept, and mostly used the RPGBot Guide for the class to guide my decisions. This helps cut down on a lot of options (especially bad ones!). Starting at a low level also helps new players, because it's more opportunity to play to learn what works and what doesn't before making a lot of character creation choices or having too many options when in combat.
The main complexities in the class are that it gets both infusions and spells. However, a low level artificer will only have two infusions they can use at once, and only a few spells. The infusions that I used didn't add much complexity to combat. Many infusions increase AC (along with some situational benefit), which is not much more complicated than having a shield. The other infusion I used was on my weapon, Returning Weapon, which I didn't have to think about any more than a regular ranged weapon.
Spells prepared and infusions used can be swapped on a long rest and one infusion known can be swapped on a level up (making it not too punishing if you make mistakes with either). When I played, I kept the same infusions and mostly the same spells each day, which made things drastically simpler.
In addition to that, many artificers will control a "pet". At the beginning that would only be a Steel Defender or a Cannon, though any wealthy artificer can have a Homunculus Servant (though it may be a good suggestion for a new player to not take that infusion). Having a pet adds some complexity, but, in my experience with the Steel Defender, it doesn't add much complexity as it has so few options of its own: it only moves, attacks, and reacts to attacks.
You, and the other players, can also help ease a new player into their role in the party, such as by giving suggestions, reminders, and reassurance when playing. For example:
In general, an Artificer isn't much more complex than any of the other arcane casters. Bards, Wizards, and Sorcerors are all full casters with many more spells than the Artificer, with the Sorceror having the added complexity of metamagic and the Bard the co.plexity of managing their Bardic Inspiration dice on top of that; Warlocks get invocations which offer a similar level of complexity to an Artificer's Infusions, while their simplified spellcasting system with a limited number of slots trades resource tracking complexity for resource utilisation complexity (determining if the situation warrants a use of their one of their much more limited spell slots). Artificers, by contrast, are half-casters who get fewer, lower-levelled spells than Bards, Sorcerors and Wizards, and more spell slots than Warlocks.
In general, the biggest piece of complexity for an Artificer will come during a long rest, when the get to decide if they want to continue with their current "build", or if they want to change up their prepared spells and/or infused items. Once that's been done, playing them on an adventure is pretty straightforward, since they're just martially-oriented spellcasters, and most of their non-spellcasting powers are passive buffs.
In fact, I would say that the closest comparison in terms of gameplay complexity would be the other half-caster classes like Paladin or Ranger. Many of the most-used Artificer Infusions can be directly compared to Fighting Styles (both the Defense Fighting Style and the Enhanced Defense infusion give +1 AC, the Archery or Thrown Weapon Fighting Styles are comparable to the Repeating Shot or Returning Weapon Infusions, etc). Artificer spell preparation is directly analogous to that of divine spellcasters, and I would argue that the Artificer is typically less complex in play than the Paladin, because the Paladin also needs to manage his Divine Smites and Channel divinity uses.
