The scoring is meant to balance out the strengths of different roles and to award points for winning and good team play, primarily. The scoring also attempts to decrease the benefits of things like smurfing or gold farming.
The exact scoring mechanism is slightly complicated, but in general you will get points in the following way:
Wins - 25 points for a game you've won.
Team Gold: 10-35 points. Decreases relative to the amount of total gold. In other words, the amount of points you get per new unit of gold decreases the more gold you get during a game. In practice, this means you get a lot of points early on and less and less the more gold your team accrues. The purpose is to avoid giving out points just based on a game being long.
Modified KDA: 0-30 points. Personal performance based on Kills, Deaths and Assists. This is a modified version of the regular KDA score (Kills + Assists/Deaths). Instead, less weight is given to Assists and Deaths are not penalized as much.
Game Length: 1-25 points. Winning short games or losing long games give you more points. In other words, if you win, you get more points for a short game and less points for winning a long game. On the other hand, if you lose, you get more points for a long game and less points for losing a short game.
The points are then calculated and summed up per game. Your three highest scored games for the day are counted in the daily ladder.
We've tried to strike a balance between rewarding the team's performance as a whole and your personal performance. As you can probably appreciate, no scoring or points system will ever be perfect. There will always be pros and cons for different players at different times. In any case, our goal is to award team play, wins, and fair matches. While not neglecting great plays from individual players.
Thoughts, questions or suggestions? We're happy to hear your feedback!