[RPG] What are the impacts of changing a Ranger’s spellcasting ability

Rangers Don't Get Foci

All classes that use a focus have a "Spellcasting Focus" subheading to their Spellcasting (or Warlock) feature:

• Wizard (arcane focus)
• Warlock (arcane focus)
• Sorcerer (arcane focus)
• Paladin (holy symbol)
• Druid (druidic focus)
• Cleric (holy symbol)
• Bard (musical instrument)

The wizards feature for instance reads:

SPELLCASTING FOCUS

You can use an arcane focus (found in chapter 5) as a spellcasting focus for your wizard spells.

PHB 114

With the exception of the Ranger and Eldritch Knight, which specifically don't mention foci as part of the spell casting feature. Who have no such text.

It Is Intentional

Jeremy Crawford clarified in a tweet that the omission of focus for the ranger class is intentional. He was asked:

[D]o rangers use spellcasting foci, and/or do they need to buy component pouches at 2nd level?

And replied:

The ranger doesn't have a spellcasting focus. The trusty component pouch will do the job.

https://twitter.com/JeremyECrawford/status/687417277231267844?ref_src=twsrc%5Etfw

This makes sense as most rangers would likely have a bow. All bows, even the hand cross bow (even with Crossbow Expert), requires a free hand to load. So holding a focus would mess with the traditional ranger with bow. You keep a free hand for spells, pouch and loading firing arrows.

Mechanically

Using a bow, you have the weapon in one hand and the other on string. After you fire, your hand is free again. When you cast you pull out the components and put them back, or they are consumed, and your hand is free again. Works great with a bow. However, the arcane and druidic focus require object iterations, and you either have to drop it or spend the book keeping at the start and end of each turn.

Yes, a holy symbol could be worn and keep the hands free, likely why they did that for paladins, but they chose to go a different direction with the ranger.

Thematically

Ranger forage for food and materials, they are self reliant. It isn't hard to see them restocking their component pouch as they move through the wild area.

What about the Mistletoe?

it might be impossible to find mistletoe in the desert when a material component is needed.

The PHB says this about the component pouch:

Component Pouch. A component pouch is a small, watertight leather belt pouch that has compartments to hold all the material components and other special items you need to cast your spells, except for those components that have a specific cost (as indicated in a spell's description).

PHB 151

The pouch has all the components your spells require, and Material Components aren't consumed unless the spell says they are:

If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.

PHB 203

So, you have mistletoe once, and you have it forever -- unless your DM rules that lose it or it goes bad, etc. Then you have to buy more mistletoe or buy a new pouch. Such a thing, however, isn't in the rule.

Unearthed Arcana / Tasha's Cauldron of Everything

A recent released play test (UA), and page 57 of Tasha's Cauldron of Everything (optional rule) provides the following to the Ranger class:

Spellcasting Focus

2nd-level ranger feature (enhances Spellcasting)

You can use a druidic focus as a spellcasting focus for your ranger spells. See chapter 5, “Equipment,” of the Player’s Handbook for a list of things that count as druidic focuses.

In terms of the Balance of the class, I'd say you don't have a ton to worry about. Artificers only gain access to spells up to spell-level 4, and even then they only gain access to those spells around level 19 anyways, so regardless of which lists they can pull spells from, they're not going to get tremendously powerful magicks irrespective of their level.

There is one important consideration though: by vanilla, Artificers don't gain access to Evocation Spells. The only two evocation spells they get are Cure Wounds, a healing spell, and Continual Flame, a non-damaging spell. In fact, if you iterate over their list of spells, you'll see that there isn't a single spell they can cast that directly deals damage to anything. The closest is Mordenkainen's Faithful Hound, which summons a spectral dog which can attack enemies.

Meanwhile, Artificers do get spells like Haste, a very powerful spell that greatly improves a creature's damage potential, but which doesn't itself directly deal damage. All of the spells they get are utility in nature: healing, ability improvements, invisibility, flight, etc. Now, I can't speak to designer intent, but my sense is that this is a deliberate choice, that Artificers aren't meant to be Offensive Spellcasters.

Your change, which would effectively be allowing Artificers to gain access to offensive spells, would have pretty significant implications on the balance of the class. I hesitate to suggest it would make them overpowered at all, because A) they'd get a lot of the really powerful low-level spells way after their prime, and long after they'd be tide-turning, and B) Artificers are generally regarded as being underpowered in the first place.

But it would change how they play, and how they treat their spellcasting abilities. My general advice, then, is that you shouldn't change their spell list.

I do like the ability of giving them some cantrips, though I'd advise you continue the practice established by their spell list, and only allow them to pick non-damaging cantrips. Note that stuff like True Strike would probably be permitted, since it doesn't directly deal damage, and fits the theme of spells like Haste, which is already in the Artificer Spell List.