Things that don't really work in World of Darkness Larps

Edmund: You see, Baldrick, in order to prevent war in Europe, two superblocs developed: us, the French and the Russians on one side, and the Germans and Austro-Hungary on the other. The idea was to have two vast opposing armies, each acting as the other's deterrent. That way there could never be a war.
Baldrick: But this is a sort of a war, isn't it, sir?
Edmund: Yes, that's right. You see, there was a tiny flaw in the plan.
George: What was that, sir?
Edmund: It was bollocks.

The first thing that i must tell you is that it is very difficult to concentrate on writing, with Eddie Izzard playing in the background.

Well, it is.

So, There are a couple of things on my mind these days about larps and larping, Specifically, what elements make a larp good, or make it bad. There are a few things that i have seen in larps that may work for others, but in the cases that i have seen these are a few things that did not work.

Treaties
One of the reasons that cross-genre Larps don't seem to work is that in order for players to be able to interact with one another there have to be some kind of treaties in place in order to prevent open warfare from breaking out between the various forms of supernatural critters. In tabletop games this is perfectly fine. In Larps, it's just silly.
Unfortunately, there's no really good fix for this. If you allow treaties, then you have weird situations where supernaturals who would NEVER cooperate with one another, end up cooperating. If you don't allow treaties, then all your players balkanize and sequester themselves away from the other types. And then you've got 4 or 5 seperate games going on.
A possible fix for this problem is to attack it with troupe style play. Make everybody in the larp roll up a creature of every type and then maybe rotate the various games around. That way if a treaty gets broken it's a major event instead of a weekly occurence.
This is the same reason why Sabbat/Camarilla larps don't work and rarely last. Con larps where the two sides are forced to work togeter for any reason are usually also incredibly lame. In addition, there is usually marked surprise on the part of storytellers when the two groups DON'T work together as scripted. This would seem to apply to games where the Crone and the Sanctified ought to work together. As I always say. Plan events, DON'T plan reactions to events.

Well Run Cities
Nobody believes in them. They stretch the bounds of suspension of disbelief. Nobody is willing to credit the idea that a city has had a single group in power for centuries and that the place has run like a well oiled machine UP UNTIL TONIGHT! it's just too far to go. Build some political instability into city histories and find ways to plug in age old rivalries and political machinations.
And here's a tip for all you would be Vampire Princes out there. You don't want the city to run like a top. There, I said it. When you are prince, or whatever passes for a local authority in another genre of games, the LAST thing you want is to be too "good" at your job. There are many reasons for this:
1) Well run cities are DULL. By crushing every conflict, you are making the game uninteresting.
2) People will bring you every single problem (Part of the job really, but if you're too good at it, you'll never rest.
3) It leaves you exposed and sets you up for crucifixion if you do screw up.

The best thing you can do as Prince, is to keep the various factions at one another's throats without actually letting them kill one another. To play them off one another, so that they can't see what you're doing. Favor one, crush another. Then next week do the opposite. Scare them with your unpredictability. political unity among the undead makes for dull story telling. Ideally, you want a situation where even in situations where unity might be called for, you'll want at least a small group trying to dime out the other vampires to the hunters.

Too Many Fruitbats
Each and every GM knows this problem. Either they have trouble saying no, or they have someone on their staff who has trouble saying no and as result, you have too many odd or overspecialized types of critters running around but nobody bothering to play the "Pedestrian" types. Most large larp organizations disallow such shenanigans or make the approval process so epic and byzantine that most give up. But the smaller game GM may not have such recourse. And most GM can only take so much importuning before they give in to Precious Princess Snowflake and give that player the thumbs up.
You know, many players forget that there can be great strength in leaning into a stereotype. I've been in games that sported 3 Daughters of Cacophony but not a single Ventrue or Toreador. And while i must give points to the ladies who played those concepts, the game overall suffered from missing vital elements of kindred society. Namely, the Clans that most desired stability.
Heck, there was a point in a certain Larp where the bulk of the players seemed to be interested in playing Tremere and there was only 3 Ventrue (including myself) in town. I got to be the primogen by dint of being the only one interested in the job. But by the time i was through, the game was crawling with Ventrue. I like to kid myself into thinking it was because i showed them how cool they can be played.
Look, if you're coming into a larp, ask around about what's already represented in the game. If the basic stuff has been covered, then MAYBE you could ask about something kooky. But if NOBODY likes playing a Nosferatu, try playing a Nos, you'll basically have their niche in kindred society all staked out for yourself...Err. maybe i should re-phrase that.

Nope. I can't be arsed.

Too many Europeans
I realize that the United States of America is a relatively young nation. 400+ and change is fairly young on the old timeline of the world. And sure it's possible that there are some real elders floating around who predate the US, but your vampire court, unless it's a MAJOR american city shouldn't be lousy with Eurotrash. I can't count the number of Alexanders and Sebastians that i've bumped into in larps of varying sizes. (and only a few of them could actualy pull that shit off. Tip: Look through a Name dictionary and find something not altogether beat to death.)
Honestly, your hometown shouldn't be hip deep in elders of any nationality, but when you don't have enough American elders or ancillae in a city, it actually detracts from the mystique that Elders ought to carry. I have only once seen a Prince of a City who was a Native American..
Not all Elders need to be snooty, or upscale, or european, or a european wannabe. One of the longest running characters i've had the pleasure of seeing in larp was a blacksmith in life and half indian. and nobody expected him to be as old, or as potent as he was.

Gang Mentality
I've not seen this small larps so much. It seems that bigger larps tend to suffer from this one more often. Someone gets their feelings hurt, they go round up their posse, and then they roll the offender and devil take the consequences. Heaven help the Prince/Bishop/Whatever who tries to actually enforce the LAWS. That sort of thing just gets in the way of the carnage based fun. Feel bad for the Elder who decides to teach the neonates a lesson by harming their backgrounds/merits, only to find 10 of them camped out on his doorstep with a dozen molotovs and a Prince who either won't,or worse, CAN'T stop them.
Feel bad for the more subtle players when a game like reaches the point-and-shoot stage of things. Players who fall into the trap of using violence to solve every problem eventually run into a problem that can't be rumbled out of existence...and then the whining starts.
The only way this can beaten is to inculcate in your players the idea that there are some problems that simply will not yield to force of arms, and stick to your guns. Force your players to deal with the mental level and the social level of Larp or all they will spend their points on is combat powers. At that point you might as well be playing live action X-Box.
I've spoken in the past about the concept of the flashpoint, Get enough clueful players in a larp and it will take off and create a life of it's own. the obverse is also sadly true. Get enough combat meatheads in your larp, and they'll start offing one another in order to have something to do, if you don't provide them with handy (slam-dunkable) targets.

Dilution of Thematic Elements
What is the point of playing Vampire? Why are Vampires Cool?
Some would say that they are powerful, passionate, they live outside normal living society, They have powers beyond mortal ken and a larger understanding of the way the world really works than John Q Meatsack.
But this is only half of the game. It's too easy to fall into the trap of playing "superheroes with fangs" and leave aside the things that are maybe a little icky,uncomfortable, and decidedly un-fun to the twinky crowd.
Sure Vampires are all the things i described above, But what else are they?
They are lonely.
They are outside God's grace...and know it.
They are unable to trust one another.
They are passionate creatures, but that passionate fire comes at the cost of occasional lapses in self control. a slavering beast within that threatens to eat their personality bit by tiny bit in it's endless search for blood.
They live a life of lies and violence and serial-almost rape and murder.
Vampires are people who are in the slow inexorable process of forgetting how to be human. and that fall is a painful one all the way down. You'll hit every single branch.

That this stuff gets lost in the shuffle in favor of twinkiness is an honest tragedy.

Sono Finito.