The Gamification settings are all enabled by default. To disable them:
Sign in to your TalentCards account as an Administrator.
Open the top-left side menu.
Go to App Control (1).
On the left-side panel, click Gamification (2).
From there, you can disable or enable either one of the user Leaderboard options, All-time (3) and Seasonal (4).
Read this article if you want to change the Gamification settings of a specific card set.