A leaderboard is a concept of a scoreboard showing the ranked names and current scores or any other data points of the leading competitors. This is very much essential to the world of mobile games. 

Leaderboards can encourage healthy competition in a game by openly displaying the current ranking of each game player. They also provide a clear way to view the ongoing achievements of the entire game players as players move towards the goal. This can lead to healthy competition.

When testing leaderboards in a game, it's important to cover a range of scenarios to ensure that the leaderboard functionality is working perfectly. Here are some test cases that might be considered for leaderboard testing:

Basic Features: Verify that the leaderboard displays the correct information for players. 

Check that player names are displayed correctly.

Confirm that scores are accurate and properly ranked.

Score Submission: Test submitting scores for different game scenarios (like winning, losing, achieving specific goals, etc.). Verify that scores are accurately updated on the leaderboard after submission.

Ranking: Test leaderboard ranking based on different criteria (like winning, losing, achieving specific goals, etc.). Confirm that the ranking order (ascending or descending) is correct.

Ties Handling: Test scenarios where players have the same score. Confirm that the leaderboard handles ties appropriately, considering secondary criteria like the time of submission (or as requirements).

Pagination: If the leaderboard has multiple pages, test navigation between pages. If there is just a loader test the loader does not take much time to load the next page’s information. If there is a specific dataset that comes after scrolling, verify the dataset is loading correctly and showing correct information. 

Filtering: Test if any filtering options are provided by the leaderboard (like daily, weekly, monthly, or any other filter) to confirm that the displayed results match the selected filter.

Player Profile: Test clicking on a player's name to view their profile and its match with both profile and leaderboard. Verify that the player's detailed information and scores are accurate and all information on the profile matches with the leaderboard.

Security test: Ensure that the leaderboard data is secure and not susceptible to unauthorized access or manipulation.

Responsiveness test: Test the leaderboard's responsiveness on different devices and screen sizes. Confirm that the layout adjusts appropriately for various resolutions.

Performance & Load test: Test the leaderboard's performance and load test with a large number of entries. Verify that the leaderboard loads quickly and efficiently.

Localization: If the game supports multiple languages, test the leaderboard's display in different languages.

Verify that the translated text is accurate and doesn’t overlap the UI.

Score Updates and Refresh: Test how frequently the leaderboard updates with new scores.

Confirm that the leaderboard refreshes correctly when a new score is submitted.

Cross-Platform Compatibility: If the game is available on multiple platforms (like, mobile, tab, PC, console), test the leaderboard on each platform. Confirm that scores are the same for each platform.

Error Handling: Test scenarios where there are network issues or server errors during score submission.

Verify that appropriate error messages are displayed and that the user is informed of the issue they are facing.

Integration with Achievements: If the game has an achievements system that reflects the leaderboard, test how the leaderboard acts with the achievements.

Delete Scores: Test the process of removing scores, [if applicable] like, if a user deletes their account and removes all their existence. Confirm that removed scores are no longer displayed on the leaderboard.

By thoroughly testing these scenarios, we can ensure that the leaderboard functionality in the game is accurate, and provides a positive user experience.