Students need to be supported in the development of their information literacy (IL) skills − the ability to seek, locate, evaluate and navigate information effectively. Usually IL instruction takes the form of traditional face-to-face sessions at libraries. Today, however, young students demand a more engaging form of learning. Recognizing the limitations of traditional classroom instruction, educators have begun to look for alternatives, and have turned to digital games as teaching tools. The use of digital games for educational purposes is often referred to as digital game-based learning (DGBL). However, the affective aspects of learning are often neglected in DGBL. A common way to address the issue is to use embodied agents (EAs), the approach taken in this thesis.Libraries should actively engage students to understand their needs to better ensure success and high levels of user acceptance to the IL games. However, students as end-users rarely participated in IL game design. Furthermore, there is a dearth of research in the use of affective EAs in DGBL, including its use in IL games. While DGBL has been shown to be an effective teaching tool, its synergy with affective EAs needs to be further examined. Moreover, the benefits of using DGBL or affective EAs in IL education are mostly anecdotal, and there is more speculation than evidence. Hence, research is needed to tease out which aspects are useful to improve students' learning performance. Therefore, this thesis asks two research questions.The first is: how can the participatory design (PD) approach be used to inform the design of an IL game with affective EAs? The second is: how does the use of affective EAs in an IL game influence tertiary students' learning?Two studies were carried out to address the two questions. Study I addressed the first research question, where Library Escape, an IL game that incorporated affective EAs was xiii designed, based on pedagogical and game design principles. A PD approach was used in the IL game design. Specifically, three rounds of focus group discussion were conducted, which yielded a low-fidelity prototype. Thereafter, individual user interviews with ten tertiary students were held to refine the low-fidelity prototype, resulting in a high-fidelity prototype.Study II addressed the second research question, where the influence of affective EAs in the IL game was examined, in an experiment and supplementary qualitative interviews. In total, 159 tertiary students participated in the pretest-posttest between-subjects experiment. Eight participants were invited for qualitative interviews after the experiment, and their feedback on the IL game and affective EA was gathered and summarized. The results showed that using the affective EA had a strong positive impact on students' learning motivation (attention, confidence, and satisfaction), enjoyment (affective, cognitive and behavioral enjoyment), perceived usefulness and behavioral intention (to learn more about IL, to recommend the game to others, and to play other IL games)....