A.

I've read that it's a positive thing. I can only imagine such a symbol would be positive.

I too have a trident on both my palms. Both at the end of my heart lines. The one on my left hand is more prominent.

So far I haven't seen anything extraordinary in my life but I've been generally lucky I guess.

I have one on my mind line on my left hand. It symbolizes strength, as Neptune has a trident and he is very strong. I have one on my left hand and not fully formed on my right, and a writers fork on my left.

I have tassels on my heart line that almost look like they form a trident but they look more like tassels, which have a negative meaning, I think meaning many ranging emotional nature's.

I also have a trident on my life line on my right hand. At the start of my life line it is chained and broken and merged with my mind line. I was very sick when I was younger, and I am now doing yoga and improving my health which has already improved greatly since birth. I can envision having even better health in the future if I keep up with yoga ad healthy living, which could be indicated by the fork at the end of the fork on my right hand. The trident is formed like am Algiz symbol or a diamond shape off of the life line and with splits in the life line. The one on the life line is curved and the on the mind like is more fork like(sqaure).

I also have a trident too...well, two actually.
On my right hand, the had line ends in a trident, with the bottom line extending to touch the Luna mount.
And my life line ends in a narrower trident that nearly touches my wrist line.

I agree that there's a surprising lack of information on this on the Internet, compared to other signs and symbols.