dnd-5espellcastingterminology
I saw in a recent answer a reference to 1/3 casters and 1/2 casters, and have never encountered this terminology before:
Paladin's are known as 1/2 casters, so their spell progression isn't as big as full casters.
What does it mean to be a 1/3 caster vs a 1/2 caster vs a full caster? How does one distinguish between the three, and which classes correspond to which types of caster?
While both members of the shadow community, a fence and a fixer operate at different levels of it and have different roles.
A fence is a merchant dealing in black and grey market goods. They operate on the fringes of the shadow community - offering services to both members of the shadow community and the more garden-variety criminal. Depending on their specialization, they may even sell to normal people; in some environments, staples of life have to come in via less-than-legal channels. A fence can hook you up. They frequently but not always have corporate contacts, albeit unofficial. ("It fell off the back of a truck.")
In some cases a fixer operates as Mr. Johnson, in others he merely connects shadowrunners with one. No matter what, a fixer is embedded much more deeply in the shadow community. They deal in information, not merchandise, and that information is who's-who in the shadow community. A fixer knows the services an individual shadowrunner can provide, the kind of jobs they prefer to take, and the other runners in a local shadow community they can/will work with.
A significant difference is how shadowrunners interact with them. Generally, the shadowrunner approaches the fence. Unless you've made a whole lot of noise on a run, a fence isn't going to know what you've got to sell (or want to buy) until you tell him. By contrast, a fixer comes to you. The Johnson comes to him, and he reaches out to his network of shadowrunners to find the right team for the job.
The same person can operate as both a fixer and a fence. That's one person with two roles, it doesn't make the two roles into one.
I've noticed the same thing, that is people using the term "house rule" in contexts that seem to be outside the lines I consider them to cover.
GMs do a lot of things - they set down rules acknowledged to be always in effect, they make judgement calls when using existing rules ("Is my familiar an animal for purposes of thing X or does it not count because it's a 'magical beast'?"), and they create new content for the game (among others).
Generally, a difference is drawn between rules, even house rules, and rulings, and content creation. Let's investigate what some games explicitly say about it. Most comments about house rules come from D&D and its variants, one might speculate that it's because other games have a surrounding culture that is a lot less, uh... discriminating... about the exact pedigree of a specific bit of game. These quotes are from recent versions but they reflect the convention in Basic/1e/2e to my recollection and experience.
Pathfinder talks about house rules and rule arbitration as two different but related activities:
In addition to these roles, the Game Master might also fill a handful of others. Many groups maintain a set of house rules for their games, and the Game Master has the final say on particular interpretations and arbitrations of rules (though everyone in the group should be aware of any house rules beforehand). - Pathfinder Gamemastery Guide, p.8
Establish House Rules: If your house rules differ from the main rules, make sure everyone knows about it. Also, be sure to let your players know that this isn’t a sport, and that you reserve the right to bend or break the rules for the sake of the game from time to time, with the understanding that your intention isn’t to be unfair, but rather to make things more fun for the group as a whole. - Pathfinder Gamemastery Guide, p.76
4e strikes a stark contrast between rules arbitration and house rules:
Creating House Rules As Dungeon Master, you wear several hats: storyteller, rules arbiter, actor, adventure designer, and writer. Some DMs like to add a sixth hat to that stack: rules designer. - D&D Dungeon Masters Guide (4e) p.189
There the section on creating house rules calls out being rules arbiter as a separate, required activity, and then has a whole section on house rules as a discrete optional activity.
Same thing with 3.5e:
CHANGING THE RULES Beyond simply adjudicating, sometimes you are going to want to change things. That’s okay. However, changing the rules is a challenge for a DM with only a little experience. Altering the Way Things Work Every rule in the Player’s Handbook was written for a reason. That doesn’t mean you can’t change some rules for your own game. Perhaps your players don’t like the way initiative is determined, or you find that the rules for learning new spells are too limiting. Rules that you change for your own game are called house rules. Given the creativity of gamers, almost every campaign will, in time, develop its own house rules. - D&D Dungeon Masters Guide (3.5e) p.14
But it's not always so simple. I've heard people refer to GM content creation as "house ruling," which I always thought was just plain wrongheaded, but in OSRIC, I noticed that while they refer to house rules in the usual "rule mod" sense (e.g. removing demihuman level limits) they also refer to creating a new magic item not in the book as "house ruling" an item.
if the GM chooses to house-rule a magic item or spell which has the effect hold undead(...) - OSRIC p.237
This is very interesting because it can be seen to use an expanded definition of house ruling - it's still net new "written down" stuff but expands it past where most people do.
In a game, there's "the world as the characters experience it" and there's "the stuff written down in the books." In that sense, you can interpret any gap between the two - which consists of a) rulings and arbitration around existing rules, b) net-new rules or modifications to rules, and c) content created that's not in those rules (even though the rules allow for creation of content) as "house rules..." But in the end that's not super helpful because those three activities are very different and most games acknowledge them as different.
Rulings aren't always "for forever," they can be situational, though of course the characters (and the players) do tend to start interpreting the world in the light of rulings so they are as powerful in crafting the experience as new rules. I had a player who got grabbed by a choker, which grapples around the neck and the victim can't talk/spellcast. I let him use his two-handed weapon while grappled since the grapple was described as "around the neck." When it happened to him again later, I had to decide whether that ruling was really going to stand every time or whether it was situational.
House rules is generally meant, as is proven by game book quotes, to be a more codified and permanent set of larger scale changes to the game. "You should let new players know about house rules" doesn't mean "you should let them know about every rule interpretation ever conceived of by the group," that's silly. The general use of this term clearly implies "large chunk" rules - these rules are gone or significantly modified (e.g. no demihuman level limits), rules options off limits or whatever.
Content creation is content creation; lumping it in with the other two is really unhelpful as the processes are completely different. It's like saying you're modding Fallout 4 when you're using the settlement building system to build settlements - it's just misleading. "Home brew" is the more correct term to use to indicate self-generated content - e.g. "my homebrewed catgirl race."
So while I've also heard people use "house rules" to mean both rulings and content creation, I think that interpretation is provably fringe/"wrong" as much as any human usage of language can be considered to be "wrong".
Many fifth edition players are new to the game, and cargo-cult terms (same thing with RAW and RAI, we saw a lot of confused misuse of them in early 5e questions) without fully understanding them. I don't think it has much to do with 5e being more ruling-friendly except inasmuch as the topic comes up more than if you're playing a more legalistic game. House rules were much rarer in 3e/4e than in previous eds, so it's also possible that becoming less used to the term over the last 15 years has contributed to its misuse now that it's revived.
Best Answer
"1/X Caster" is shorthand for how quickly a character gains "spellcaster levels" (and with them, more spell slots)
The progression for each of these spellcaster types looks like this, with the first column representing Character Level as a Single-classed X and the other columns representing the "Spellcaster Level" they have as that Single-classed X at a given level.
The classes that fall into these categories are:
*The Artificer is a Half-Spellcaster, but unlike other Half Spellcasters, they gain their spellcasting feature at level 1, instead of level 2, and are treated like level 1 spellcasters at that level.
†Warlocks are unique in that their spell access resembles that of a Full Spellcaster, but their Spell Slots are completely divorced from the system that all other spellcasters use, so they need their own category.
Your spellcaster level determines how many spell slots you have, and the maximum level of spell slot that you'll have will (usually) be half your spellcasting level, rounded up.
So if you're a level 9 Paladin (Half Spellcaster), you have a Spellcaster level of 5 (See the Character Level 9 row for a Half Spellcaster). Therefore, you have spell slots equivalent to a level 5 Cleric (Full Spellcaster) and to a level 13 (or 14 or 15) Eldritch Knight (Third Spellcaster)—and for each of these characters, their Spell Slot total is:
"1/X Caster" also comes into play in the Multiclassing Rules
What kind of Spellcaster you are affects how your levels are added together when you Multiclass into multiple kinds of spellcaster.
†Artificers have a special rule: when adding their levels for multiclassing purposes, you round up after dividing by two, instead of rounding down. Note also that Warlocks are not included in this list; again, their Spellcasting is completely different from other classes, so they aren't considered in calculating a character's normal spellcasting level.
For example, suppose we have a Multiclassed Wizard 5/Eldritch Knight 11. We add their levels by first dividing them by the level of spellcaster they are, so we take 5 Wizard Levels (5 * 1/1 = 5) and 11 Eldritch Knight Levels (11 * 1/3 = 3.666 → Rounded Down to 3) and add them together to find that this character is the equivalent of a Level 8 Spellcaster, gaining 4 1st Level Slots, 3 2nd Level Slots, 3 3rd Level Slots, and 2 4th Level Slots.