alt Hacker News"Score: 5, Troll" is the ultimate achievement.
To put it that into context, some tags count as upvotes, others count as downvotes, "Troll" is a downvote. So to have your post labelled as "Troll" with a positive score, it has to have enough upvotes to compensate the penalty from the "Troll" votes, but without having another tag dominate. 5 is the maximum score.
"Score: 5, Troll" is therefore the mark of a very successful troll.
They also have "Underrated" and "Overrated" which apply points but do not act as tags. So I guess the easiest way to get +5 Troll is to have many Troll and Underrated votes, if it works the way I think it does.