As a descriptor. LRP is closer to “sport” than “role-playing game”. This is because club games, 30 person intense interactives, and fest LRPs are actually entirely different experiences lumped together by a couple of basic shared attributes.
(From a Facebook post by Mr Andy Raff. Probably friends-only, but I figure he won’t mind if I put it here to remember it. I agree with him, anyway.)
LARP experience 
I’m not actually entirely certain what you mean by club games, intense interactives, and fest LRPs. Are these more like theater/parlor LARPs? A few questions — what makes them close to sports than role playing games? And if lots of people using the word “LRP” to include them, aren’t the more sports-like activities the odd one out? Isn’t the definition then “activities which share these common attributes”?
Oh, the dangers of sharing with a vocabulary that isn’t as shared as you assumed!
These are UK-specific terms, I guess.
club games – run often, weekly/monthly, with “a few” player characters per event, out of a club population of dozens, usually in a single persistent world, significant interactions generally involve NPCs, usually feature more complex rulesets, usually run live-combat “adventures” perhaps backed-up with lower combat “tavern nights”, which are in experience more like parlor LARPs.
intense interactives – run more sparingly, perhaps in uniquely designed worlds, significant interactions generally do not involve NPCs, usually feature less complex rulesets, usually with less or even no combat, and in experience are more like I understand theatre/parlor LARPs to be.
fest LRPs – run periodically, with “hundreds of” player characters per event, significant interactions generally do not involve NPCs, usually feature less complex rulesets, usually run large live-combat “encounters”, and are in experience are a bit like several parlor LARPs at the same time, in the same place.
All of them are role-playing games. (*)
The thing I agreed with in Andy’s original notion, was that _actually_ the term role-playing game isn’t terribly helpful as a means of description, as a means of informing the prospective player what they are to expect. The activities they-the-player will be engaged in in those very different types of events are _so_ different, that the shared element of roleplaying is rather small. Even in attempting to define my terms, I used a good handful of variables.
So, I could sign up to a fest larp, expecting the “role-playing game” I am used to at my club event, and be extremely disappointed at the lack of action, the lack of specific focus on me, the lack of organiser-delivered activity per unit time spent in the world etc. I would be at a role-playing event.
Or, I could sign up to a club event, expecting something based primarily around my experience of a fest LRP, or an intense interactive, or.. or… or…
If I had to tell people what to expect, I’d probably not use the descriptor at all, I might start with…
It is a club game – you will be running around in a wood, hitting orcs…
It is a intense interactive – it’s like being in a stage drama with no audience…
It is a fest LRP – imagine you’re a character in a big soap opera or mini-series…
It’s not that individual LRP styles are more or less like sports – although they are. It’s that “roleplaying game” isn’t a very good word to describe what you actually do at them.
Different styles of LRP may all be role-playing games, but actually –
They have as much in common as tennis and football, as opposed to – say – cricket and baseball, let alone basketball and netball.
Or, tl;dr “Boffer and theatre style larps are so different that calling them both role-playing games is as informative as describing both baseball and football as ball games.” How’s that?
(* At least in that all of them have people pretending to be other people: although there’s nothing I guess _inherent_ to that, and any of those games _might be_ based in alternate worlds where the person you are pretending to be is “you-in-that-world.”… That’s another post. At least one more.)
(And thank you very much for commenting. I enjoyed trying to untangle my thoughts a bit.)
Very interesting! Someday I’d like to try all of these styles.
I agree that the term “roleplaying game” is a very broad term — typically, when I hear “roleplaying game” by itself, I assume people are talking about tabletop RPGs of the D&D variety. LARP (or LRP) would be a subset of RPGs, but also an extremely broad term. Just like “sport” is a very broad term, and if someone says “let’s play a sport” that doesn’t tell you much about the experience you’ll be having (tennis? baseball? football? bowling?), saying “let’s play a LARP” also leaves open a broad spectrum of possible experiences.
I think I misunderstood your original post to mean “therefore let’s not say they all count as LARPs” but now I think what you mean is, “let’s use more specific terminology more often so people can have more productive conversations and make better informed choices.” Which makes sense to me!
(I would actually say that pretending to be someone other than yourself is inherently a part of LARP — if you’re simply you-in-that-world then it’s an ARG — alternate reality game — but even that isn’t a binary thing. There’s a spectrum between playing yourself and playing someone else. For example, in a zombie game, I was playing an altered version of myself, one who became a journalist. Is that a LARP or an ARG or both or neither or somewhere in the gray space in between?)
That last comment of yours really resonates – in fact, it’s very similar to where the debate got to over on Facebook.
There’s no binaries here, really It’s all shades of grey.
Other adjacent experiences too – say, https://en.wikipedia.org/wiki/Escape_room for example – or Secret Cinema – http://www.telegraph.co.uk/film/star-wars–the-empire-strikes-back/secret-cinema/ – in neither do you have to roleplay being someone else, but you can.