Being that it was printed before 1991, it lacks most of the security features found in later bills. One way to check is to take a close look at the paper itself. A genuine bill should have little red and blue threads mixed into the paper. If you're still unsure, you can bring it to a bank for authentication. They have pens with specialized ink to check for fake bills.
It is a common $100 bill in circulation and has a value of $100.
no
There is no trick. I would recommend finding an example on ebay and just making sure that the colors and fonts are the same.
100usd
yes... it is real ... i have one of it...
$5.75
1985 bills don't have security strips. They were first used in 1990.
no
No. Security strips were added starting with the 1990 series.
Please check the date on your bill again and post a new, separate question. The last red-seal $100 US Notes were dated 1966. Any 1985 US $100 bill should have a green seal and the words "Federal Reserve Note" across the top.
I have a 1977 $100 bill and want to know the current value of it
as of February 18, 2012, a 1000 peso Mexican bill from 1985 is worth about 75 cents.