So, a question for pre-4e DnD players ... what was "attrition" like in those editions? Because it's being viewed as a core part of the game, and admittedly, I only have a bit of 3.5 experience. And there, at least for me, the assumption was only spell caster spell slots are attritted (which, of course led to discussion of 5 minute workdays). Generally, it was rare to start a fight with less than full HP or within a few HP from full.
This mirrors my 4e experience, where only daily resources are a part of "attrition". And that was fine, a feature even. Knowing PCs had a solid budget of encounter powers and healing surges meant they rolled initiative with full HP was what made the combat engine and encounter balancing so good and easy.
Mostly going to taslk 3.x but some 2e towards the end... It kinda was and was not attrition based but
resource expenditure was much more meaningful. It's easy to look at some of the spells & say "omg this is insane", but the mechanics made it very different because every spell slot needed to be prepared individually & was not something you were generally capable of swapping to some other spell.
The best example I can give to explain is to describe one of those exceptions given to cleric. In 3.5 (maybe earlier?) a cleric could swap a cure wounds into some other prepared slot so they could prep say a 2nd level
lesser restoration & cast a second level
cure moderate wounds. Doing that meant the cleric couldn't cast lesser restoration with some other unused slot because it was probably devoted to a spell like
Bear's Endurance or whatever.
With every slot assigned ahead of time it was easy (and common) to have a wizard or whatever prepare one of those very powerful spells & resist using it because they didn't feel that a particular encounter deserved their break glass in case of emergency spell. Likewise A spellcaster would almost always have some spells that just went unused that day after being prepped, especually spotlight drawing spells. One of the easiest ways for a spellcaster to get around that was to focus on spells that gave everyone else a brighter spotlight & there's a great video talking about that
here.
With the spell prep differences that went with vancian spell casting along with limited & almost always nearly useless cantrips that leads into ways of coloring outside those lines with things like scrolls potions & wands like were mentioned in posts 193 & 195. Those absolutely existed, but the posts are misleading & only telling half the story. A spellcaster would often invest a good chunk of their share from the party's income in scribing scrolls (usually wizards because of the requirements to scribe a scroll). Casting from a scroll had a lot of downsides (lower DC/lower spellcaster level/etc) unless unrealistic amounts of gold were dumped into it to avoid some of the downsides the scroll brought & that meant a lot of those spell scrolls built up were niche spells scribed just in case that oddball situation comes up & they need to cast knock create water or whatever* even though the rogue could unlock stuff no cost & the ranger or druid could probably find water if the party needed to.
Sometimes scrolls could serve to extend the spellcaster's stamina in how many fights or how strong a fight they could handle, but that was a job usually falling to wands.... Wizards spent many turns making a sling attack to preserve resources.
Wands like the ever present & well known wand of cure light wounds that's already been mentioned. Wands came from about 4ish places that came down to being two main sources (A:treasure/NPC granted quest rewards & B:buying/crafting.). In the case of treasure & quest rewards from NPCs or whatever it was ultimately a way for the GM to tune the difficulty on their campaign a bit by providing extra resources & what is provided can be withheld by the same whimsy the GM used providing them. Since everyone knew that the GM could simply not give out more of those awesome wands if they used them too recklessly there was some incentive to hold onto them or use them slowly rather than using them as quickly as possible just to avoid using that sling on zombies or whatever.
The second way of getting those wands was to buy or craft them, again the GM had a good bit of influence over what when & how much was available but again there was reason to avoid using gold to get wands for the ability to nova through the adventuring day because gold spent on wands was gold that could not be spent on helping to fund & round out the magic item churn PCs were expected to go through. That single 750gp first level wand might not be a huge dent in a PC's
wealth by level, but burning through one every adventuring day or two would add up to a cripplingly eye watering value pretty quick.
2e was different in a lot of ways & sometimes even similar in others... but there are so many gigantic system differences that comparisons become very difficult. Even something as simple as what level a PC with X amount o f experience would be is a thing that differs from class to class just as how many spell slots a level N PC had or what they got experience from was going to differ depending on class. PCs were still vancian casters, death was much closer & so on. There was a lot of advice & lattitude given to GMs, but it wasn't always adversarial. The rules wanted your players to cooperatively succeed
with your help, but those same rules & everyone at the table wasn't going to be too broken up if some of the PCs got killed off along the way. I remember the DMG even having a line saying something about how healing potions should be readily available for PCs to purchase as an easy example that doesn't need much insight into the edition mechanics or baselines.
* I picked those two spells for being easy to describe example that didn't need much context or description of edition specific differences