Thrown shurikens have a "hilt hit".

[mgtr14]

"Hilt hit" (AFAIK) being the chance that a thrown sharp weapon deals very little damage, as if you were hit by the hilt and not the blade.

Yes, this even happens on direct hits (Without slowing down or hitting anything else). Thrown shurikens have a chance to deal a "hilt hit" instead of a normal hit. Is this intentional?

[Pricey]

I don't think this is true, unless you can provide video evidence. I've never seen this, so if it is a chance, it is extremely small, which is unlikely to be added into the game code for a weapon (i.e. like a 0.5% chance). I tested this throwing 100 shurikens, and all of them hit normally. The shuriken probably collided with something you didn't see or something small which made it lose its momentum and hit power.

[Gurt]

There's no "hilt hit" damange system in SFD.
If any thrown item (bottles, chairs, machetes, katans, guns etc...) hits anything solid it will lose it's thrown state property and go into a lesser damaging state. It's most likely it hit something on the way or clipped something or you're trying to throw them in a very tight space which forces it to hit something. A picture of how you're throwing it or a gif or a custom made map where this can be repeated is required before I will investigate any further.

[mgtr14]

I asked around if anyone else noticed these "hilt hits". I described the hilt hit to these 3 people the same as I did here.
I've also found a spot where the "hilt hit" happens, and it seems like it's touching the platform somehow. It happens frequently under platforms.
https://imgur.com/a/ESLrZgK

I've also had this happen without being under these platforms, but I have no footage. It seem like the problem is that it's hard to see when a thrown item hit something and lost it's "thrown state" because it keeps it speed. It can nudge a box and suddenly deal almost no damage. It happened so much that I just thought it was a feature, but thought it was weird to have it on shurikens too.

[Gurt]

Thanks for the extra information about platforms and the pictures It really helps.

Turns out that if a thrown item overlap platforms for a certain time they do go into a lesser damaging state. We basically have 3 damaging states for thrown items. The full one if the item hasn't hit anything, a lesser one if the thrown item has hit something and a non-damaging state if the thrown item has collided with something for a longer period (sliding/laying on the ground for example). But platforms continuously registers a hit state against items (wrongly of course) making thrown items deal less damage and eventually no damage.
I think I have a working fix for this to the next update, I just need to test it.
Fixed after v.1.2.0e