In my campaigns we typically don't rely on material components, allowing casters to use any spells as long as they have the right spell slots available. My impression is that using components would be more challenging, since players' spells would be limited by gold, component availability, and carry weight. Is it significantly more challenging or cumbersome to include this feature? How do others incorporate components?
If you are talking about the material components specifically... Most of the components are fluff, for most casters, most of the time. They choose a component pouch or an arcane focus, and they don't have to worry about the lint, sand, feathers or eye of newt. If they get separated from their focus, the materials needed can be an interesting plot point or puzzle.
Of course, if a material component has a cost, that cost must be paid. The cost of the spell prevents spam casting and may affect casters choices of spells to cast. The cost for Hero's Feast, for instance, makes it so that the party isn't constantly enjoying immunities and advantage on the savings throws. Those provide balance, by making it more painful to cast more power spells (compared to the spell level).
If you are referring to verbal and somatic components as well, I think they serve basic purposes. Somatic components are to force a free hand, and the verbal is a weakness that casters have. It means that keeping a caster prisoner includes gagging them and tying their hands.
Most of the time, it isn't something you think about -- until it is something you have to think about; or you're casting something with a cost.
To add to J. A. Streich's answer:
As he says, most of the material components are fluff, most of the time. And also, as he says, assuming you are referring to material components.
By ignoring material components, you are increasing the power and versatility of casters. Of course, D&D is a game where the rules say you can change the rules, so you are free to make the rules what you want, and what you think is fun.
You asked if it is significantly more challenging or cumbersome to use this feature. Consider three cases:
- Find Familiar
The material components are 10 gp worth of charcoal, incense, and herbs that must be consumed by fire in a brass brazier. 10gp is a significant cost to a first level character. The brass brazier is also perhaps a challenge. It isn't even listed in the equipment list in the PHB. So acquiring the components requires at least a stop in a suitable store, and perhaps work to find such as store. However, if you ignore the components, a first level character can cast find familiar right out of the gate. Either option is fine, but they are definitely different.
- Continual Flame
The material components are ruby dust worth 50gp, which the spell consumes. Ignoring the material component allows the caster to cast it at will. In some campaigns, having light underground is a challenge to be overcome. If this spell is free, it is easier to overcome the challenge. Either option is fine, but they are definitely different.
- True Resurrection
The material components include 25,000gp of diamonds, which the spell consumes. The presence of the component helps to make death-reversal magic a possibly rare commodity. Of course, since true resurrection requires at least a 17th level caster, it is already limited, but the presence of the costly component means that even well-intentioned NPC casters can reasonably ask PCs for a significant outlay in order to use the spell. Either option is fine, but they are definitely different.
So, yes, using the material component rules is significantly more challenging and cumbersome, in certain cases.
You ask how others incorporate components. I expect players to adhere pretty close to the rules. For fluff material components, they either have to have the component, or use an arcane focus. For consumable components, they have to acquire them specifically. For death-reversal magic, the cost is situation-dependent, in other words, they don't actually know how much it is going to cost until they try to cast the spell.
As they advance in levels, I allow them to hand-wave a fair amount of trivial stuff. A first level caster needs to acquire the components for find familiar specifically. A tenth level caster with lots of gold can be assumed to have stocked up at some point in the past.
Expensive material components such as "500 gp of crushed diamonds" are considered to be balancing factors for spells whose in-game and meta-game effects are not even. For instance, spells that revive the dead have varying power levels, and are sorted into spell levels based on that power level. However, quite aside from the in-game power level, they have very strong effects on the overall game. If a Cleric could simply revive anyone at any time, why would they let anyone die before their time? And so the major spell components try to balance that out a little.
These spell components are important to track, and can even make for good side adventures. "25,000gp of crushed diamond? I know he was a really good teammate, and we need him back, but where in hell are we gonna find that?"
Trivial spell components, like a pinch of sulfur rolled up in bat guano (the Fireball spell) is mostly intended for flavor.
Additionally, as this answer mentions, Spell components are literally a joke. The Fireball spell components mentioned above are also an allusion to really cheap gunpowder.
Generally, tracking these components is unnecessary, unless it was introduced as a specific plot element. "All the bats for at least a hundred miles have become tainted. The guano can't be used anymore. The Mage's Guild is in an uproar, and adventurers are needed to find the cause of this."
At that point, tracking that specific component becomes an interesting mechanic. "You've got enough prepared for 3 more fireball castings."
However, trying to track assorted bits of fluff, lengths of colored string, teeth, hair, leaves, sticks, twigs (not the same as a stick!), branches (also not the same!) and so on just turns the casters into accountants. This adds "fake difficulty" in that the characters are forced to act out a lot more of the mundane tasks required to prepare their magic. These tasks are typically uninteresting, and glossed over as "things done while resting/during downtime". Additionally, you will be facing any number of varieties of "Well I didn't know I needed to do that, but my character would have known, and he's not an idiot!"
Dungeons & Dragons is intended to be a fun game. Ledgers & Logbooks would appeal to a much smaller audience.
When I am playing a PC wizard, I find some of the components to make fun personalization. My wizard loathes wizard robes dangling with spell component pouches (because that screams “Low HP! Shoot me first!”) So I don’t just assume I can grab something weird. For example, I know where focus items are and how they are arranged. If I have prepared a spell, I know where the component is — and I avoid some spells because the components (though mundane and free) are weird and hard to keep handy).
One of my favorite spells (in a different edition) was “Zone of Cold”. Material component was a snowball. I don’t care if it’s free, how do you make (or store) a snowball? What fun — even though the DM didn’t care and I amused only myself dealing with it.
I assumed that during downtime most mundane stuff was just taken care of, unless it really was something weird.
That being said, as a DM I generally let wizards not worry about sticks and twigs and pinches of dust. But I did occasionally make it hard to find 100gp pearls for identify, but they could buy a 200gp pearl that would work...
No. All of you are missing the point of this game. You are playing Dungeons and Dragons. The rules for spells are defined clearly by the resources provided.
The rules are made for balance and changing any one rule breaks the system.
For example: Jack decides to build a wizard, his power comes from his spells, which in turn rely on components. Henry decides to make an elven ranger with a bow and arrow and leather armor. Henry's powers come from his equipment.
The group is attacked by an orcish war band and the orc sorcerer lands a luck hit with a fireball which both Henry and Jack fail their saves for. Henry's bow and arrows take enough damage and are burned beyond use. Jack's components are also burned.
Take away the rules and whats the point of the fireball? Wood is weak against fire. So are rose pedals and sun-dried frogs legs.
What if their thief decides to steal their components or replace them? Removing removing that dynamic lowers the versatility of the thief.
Just follow the rules and the game mechanics will work organically to make the magic happen. Messing with rules is pointless. Just build your own system instead.