Done well, gamification nudges the behavior you want. Done badly, it rewards noise and annoys your best members. The difference is what you choose to reward.
Reward contribution, not volume
Points and badges should recognize helpful, on-topic participation — answers, thoughtful posts, showing up — not raw message count. Leaderboards work when they celebrate the members who make the community better.
Keep it optional
Make the mechanics visible to those who care and easy to ignore for those who do not. Gamification is seasoning, not the meal.