In AD&D a turn was ten 6-second rounds during combat.
So when I read in D&D 5e that the Thief's Sneak Attack ability says "Once per turn you can deal an extra 1d6 damage", is this saying that abilities like this (e.g. Sneak Attack, Colossus Slayer, etc.) can be done every 6 seconds (i.e., once a round) or once a turn, i.e. once a minute?
My current understanding is that these abilities can be done once a minute.
But then the PHB describes a turn as an action of some sort in the round. This is where I get a little confused.
I have had discussion about this with my group of players, and I am using 1 minute turns. Am I wrong?