Secondary game objectives, optional challenges that players can choose to pursue or ignore, are a fundamental element of game design. Still, little is known about how secondary objectives affect player behavior. It is commonly believed that secondary objectives such as coins or collectible items can increase a game's flexibility, replayability, and depth. In contrast, we present results from analysis of two popular online Flash games showing that secondary objectives can easily harm the retention of many players. We support our findings with data collected from over 27,000 players through large-scale A/B tests in which we measured play time, progress, and return rate. We show that while secondary objectives can encourage long-term players to extend their playtime, they can also cause many players to play for less time. By modifying secondary objectives so that they reinforce the primary goal of the game instead of distracting from it, we are able to avoid negative consequences and still maintain the retention of long-term players. Our results suggest that secondary objectives that support the primary goal of the game are consistently useful, while secondary objectives that do not support the main goal require extensive testing to avoid negative consequences.

Erik Andersen
Yun-En Liu
Richard Snider
Roy Szeto
Seth Cooper
Zoran Popović

	On the Harmfulness of Secondary Game Objectives Erik Andersen, Yun-En Liu, Richard Snider, Roy Szeto, Seth Cooper, Zoran Popović FDG 2011 [Paper (1 MB)]
	Refraction [Project Website] [Refraction on Kongregate (Requires Adobe Flash Player 10)]
	Hello Worlds [Hello Worlds on Kongregate (Requires Adobe Flash Player 10)]