It's called a Robin Hood. No points as Boomer stated. It typically damages the shaft and/or flight.
HMMM
euro rules may differ, but in the USA, and as it's a "robbin hood", it counts...(well, it used to.. not so today.. that's efff'd up...) it counts as a "thrown dart", and does not score, and also prevents you from throwing one to replace it..( so be proud, it would hve been really cool if it was in th double bull.. a 4.. not so cool...unless that was your "out number...)
So, Boomer is correct, real bummer, but worth showing... when I was "darting" my pals, and a really close pal, were manufacturing them, in every way and composition dreamed of.. exotic metals, modular shaft and tip constructions, etc. I had awesome free bies.. I know back in the 70's-80's, we counted them during tournaments.. and they always brought free drinks when it was in the double bull... seams to have been revised at some point, in dart rulings. I've done it myself many times.. when I was a hardcore "darter".. (just an excuse to drink profusely, and toss pointy things at bars, every week, and try to win a trophy.)
Same goes in tournament Archery, which I was very into for many years... in any competition, a "Hood'ed" arrow counted as the same as the arrow it was embedded in...when shooting at a single spot target... only exception is if you were shooting a "5 Spot" target, either in a normal (300 point) competition, or a Vegas(450 point) round, which allows only "one" arrow to score, per each of the 5 target spots...(or a 3 spot Vegas target) if mistakenly firing another arrow into an already "stuck" bull, both arrows are then nullified... tough tater's sometimes, when you are on a line shooting with 100 people...
I shot arrows everyday, for almost 10 years, and competed at very high levels, had a collection of "robbin hood" arrows numbering close to 100...(so that means 200 destroyed arrows..) that gets expensive, and thus when you are at that level, you shoot 5 spot targets.. each "Hood" ends in the expense of both the arrows, which at the time in the 80's, using top line stuff, ran you about $40 each time you did it.. braggin rights, and the "ooooh ahhh's" were worth it, for a while..
When I had to "compete in a qualifier round" to get into a tournament, I bit the bullet, shot a single spot target, and got in.. but at that point, I realized a "knicked" arrow, displaced out of the bull, would net me a non winning score in a competition, I never shot single spots again... when the $$ was the outcome.
my Dart pals used to come to many of my competitions, private cheering section so to speak, they really loved watching 20 yard shots, with an arrow, to see it hit a spot the same size as the "double bull"..
I'm the "fat" guy, in the middle, white shirt, long hair, with the big beard.... I won that comp, and earned state champ kudo's. IIRC, it was my first "big" win, a perfect 300 round, and I was shooting a single spot target, and did Robbin hood an arrow, which led to many cheers, but I had to ask the officials for a pause, when it occurred, because I could not clearly see from my line position, even thru binoculars (which we all used) it was a "hood", they went down, looked, and gave a thumbs up...
oh, back to Conrads conundrum.. plastic tipped darts, are scored by the machine.... pro darts, do not have plastic tips.. I hate plastic tip darting, I go thru like 6 tips in a night, playing that stupid game..
all of us have nice bristle boards.. and have tips that pierce flesh, and cause bleeding.. not pub fair...
the guy that got me into "darting", and followed my "big darts"(archery) was the fellow that sparked this company into business... they progresed well, with designs by all of us fro the early 80's.. good stuff..
https://voksdarts.com/about 5 minutes from my house.