[InclinedPlane]

I would modify your word "friendly" to instead be "playful". Competition can be healthy, beneficial, and fun, but usually only when it's playful. Consider the difference between a couple kids playing baseball for their own amusement on the one hand and a bunch of stressed out, angry, yelling parents at a little league game. There are extremes to competition and often the point where you try to win at all costs is where things break down and the negatives have the potential to overwhelm the positives.