Friday the 13th: The Game has a robust perk system for its counselors, with each possible perk affecting two stats, one positively and one negatively. The rarer the perk, the more it helps and the less it hurts.
But can you stack perks in Friday the 13th: The Game, increasing the benefit to one stat? For example, if you have a boat-speed increase of 12% on one perk, and 10% on another perk, can you use both and make it 22% boat speed?
Unfortunately not. If you try to equip a perk that gives you one type of bonus, it will simply replace any perks you may already have that give that same type of bonus. So, in that scenario above, picking a second boat perk will simply replace the first boat perk, no matter which perk you're trying to improve.
This means that, if you have two perks that give bonuses to the same stat, you might as well sell the less valuable one.