The inaccessibility of rulebooks hinders the rule learning experience of boardgame players who are blind or low vision (BLV). We explored the design of conversational agents (CAs) to support their learning needs and provide companionship by conducting two qualitative studies. In Study 1, 14 boardgame players who are BLV first identified their rule learning challenges and co-designed desired social and functional characteristics of CAs to combat these challenges. Based on these findings, we developed a CA using Amazon Alexa and 9 players who are BLV evaluated our CA in Study 2. Our findings generated important design principles for CAs to support boardgame rule learning: conciseness, customization, social characteristics, and ease of navigation.