The act of snorting or "horking" some form of substance; (i.e. cocaine, meth, ecstasy, ketamine.. and other forms of illegal or prescription drugs.) Mainly giving yourself a "high" that could or could not be the same result that you would receive from taking any substance orally or anally.
Played in the subways, railing is when you bolt down the train tracks right after a train has left the station, all the way down to the next station. The objective, of course, is to make it to the next one alive. The traditional round is played directly after the last passenger train has left, which is trailed then by the midnight express.
I hate railing in Russia, too many cables along the tracks; you're bound to trip cost you the game!