1985-P Dime Strike Error?

thanks for the awesome response coop. the graphic helps a lot. is there any sort of market for these?

Here is an 1985 D dime I aquired that I believe is off struck? I dont know if its something to collect and save or not or the worth of it ..but wanted to show my find thats like yours

I would argue that the 1985-P dime was struck from a improperly heat treated and worn "sunken" obverse die. It appears to have been struck from one of a number of improperly heat treated obverse dies. The improper heat treating caused die sinking; manifested most prominently as flattening and excessive concavity near the rims of the coins. This effect is seen on many 1985 dimes from both Denver and Philadelphia Mints (with all the dies being made in Philadelphia during that era). The reverses of these coins are most often weakly struck from well worn dies due to poor fit-up of the dies caused by the defective obverse dies; the effect seems progressive. The areas of greatest flattening on the obverses shift around the circumference of the coins (sometimes showing strongly in more than one area) suggesting uneven heat treating from die to die involved.
Insufficiently upset planchets (or blanks) and Misaligned dies have also been identified as possible causes of these errors but the coins suggest otherwise in that this effect is largely restricted to one year/denomination, can be found in both Denver and Philadelphia Mints, appears progressive on both obverse/reverse and is so prolific.
Minor at best considering how many there are but still an error caused by a mistake in the processing of dies inside the Mint unrelated to normal die wear.

Thanks John!

Awesome explanation koinpro! I had a good time reading your response, and I learned something new from it.