Background. With the use of computer-based simulations and games becoming increasingly common in education and organizational contexts for delivering training and instruction, learners are being granted unprecedented control over their learning. This increase in learner control leaves large differences in how learners challenge themselves and explore their learning environments. Learners can benefit from task difficulty, an aspect of challenge, when they are neither overwhelmed nor underwhelmed. The purpose of the present lab study was to test a model of how encouraging learners to challenge themselves with greater task difficulty when practicing a video game could be a “double-edged sword” in terms of their skill-based learning. Method. Using a first-person shooter computer game as the criterion task, 120 undergraduate males were randomly assigned to one of two groups. Half of the participants were encouraged to practice at a difficulty level that matched their skill level, while the other half were encouraged to practice at a difficulty that greatly exceeded their skill. Exploratory behavior was reflected in the variety of weapons used. Results. Findings supported a model of inconsistent mediation predicting that difficulty encouragement instructions would lead to higher selected practice difficulty, which in turn would have positive direct effects on skill transfer yet negative indirect effects through exploratory behavior. Discussion. The present study demonstrated that encouraging learners to practice at high levels of task difficulty is a “double-edged sword.” Although high levels of task difficulty can help in the preparation for future difficulties, it can also undermine exploratory behavior which is an important aspect of the learning process. This research speaks to the potential of encouraging learners to practice under difficult conditions without undermining their learning.