In 2016, over 300 wild reindeer were killed by a single lightning strike on the Hardangervidda plateau in Norway

Electrocuted, basically:
“Lightning does not strike a point, it strikes an area,” said John Jensenius, a lightning safety specialist with the National Weather Service. “The physical flash you see strikes a point, but that lightning is radiating out as ground current and it’s very deadly.”
- That's interesting. I have seen lightning split a tree and then follow wires into a house blowing out the wall all long the path of the wires. I have also seen it lift up decking when following underground wires.
  But if lightning hits with no lightning rod and ground is equally everywhere I guess I could imagine this result.
  
  and ground is equally everywhere
  You make an interesting point; Lapland is known for being relatively flat, often stony and pretty much treeless. I'm sure that contributed to an increased radius.
  
  I read somewhere that the induced electical field shift near a lightning strike is - while orders of magnitude calmer than the strike itself - still powerful enough to burn, maim and kill.
  I think it's what Wikipedia calls "side splash" in the article on lightning injury?
  
  Here’s a question with a non-intuitive answer, do you think lightning rods attract lightning or ….
- Thank you, I didn't know that.
  
  Part of the problem is that we have two feet. When lightning strikes the ground nearby, it creates a difference in electric potential between the foot that's closest to the impact point and the more distant one. If that potential is great enough, then an electric currect can jump through one's shoe, go up into the body then down the other leg and back to ground.
  Laying down only increases the surface area in contact with the ground, so the best thing to do is get inside.

Poor creatures. That’s Norway to go.

Imagine in prehistoric times you and your posse are stalking a herd of those when all of a sudden ZAP and they just lie there medium rare
- ...along with you and your posse

This Practical Engineering video explains the concepts behind how this happened
TLDR: The electricity is trying to flow through the Earth, but a reindeer is a better conductor, so it flows up into the nearest leg and down out the furthest leg. If they were standing on one foot they might've been ok
- Don't they have four legs? The day I see a reindeer sitting on one leg I'm getting glasses
  
  Yes, a reindeer standing on one leg would be unusual, and it's the only way they could've survived this 😂

Oh deer

That's what they get for never letting poor Rudolph join in any of their reindeer games

Thor got drunk and decided he needed a steak

That's what they want you to think.
- The Night Santa Went Crazy

Damnit Thor
- He does love murder
  
  Have you read the marvel comics? I never read much avengers as a kid. Recently read some 90s Thor. Messed up man.

how does lightning work? I've seen videos of people being struck like 5 times and they are fine with some scars and minor nerve trauma. What causes that person to be ok, but 300 reindeer just die?
- You get a circular voltage gradient away from the strike spot. A human with their two legs doesn't spread along that as far as a deer's four legs do, so they catch more voltage drop across that, which also runs through their body (along their heart etc). It just depends a lot on how and where a body is affected by electricity.
  
  that's a good explanation thank you

Lightning is one of those things that makes it easy to see why people invented Gods to explain the phenomena.

What kind of ritual were they doing
- The one that seals the elder Gods into a soul cage for 1000 years.
  Sadly, the humans will never understand the necessity and impact of the caribou's sacrifice.
- They just be like that

had this happened 2000 years ago a local village would be absolutely losing their SHIT.
look at all that fucking MEAT
god has blessed us with a bountiful harvest
did you see all that fucking MEAT?!
- I don't think they would go near that.
  
  Hard to know.
  Could go either way.
  I can certainly imagine people avoiding it because of implied danger.
  ... but I can also imagine people evaluating it and concluding that "they don't look sick, and they taste fine".
  I guess the decision depends on how hungry you are.
  I think it's important to point out that anyone making this decision was probably using the herd as a primary source of food...it's pretty clearly a sign that you should hit the road.
- Way back there weren't any settlements, only nomadic tribes. They'd loose their shit alright. "Oh no, our transport and future food resources!"

wizards
- OP since original D&D.
- Area of effect what's that

Incidentally the plateau is a great hiking spot, it's obviously beautiful, not particularly overrun (compared to the Alps it's almost comically empty), there are reasonably many dnt huts - typically self service -, and free camping is explicitly allowed in Norway.