Inclusive design considers usability first: to design with the needs of everyone to decrease the mismatch between the end-user and the design object. In advertising, the mismatch may be in the opportunity to process an advertisement due to design strategies (i.e., executional ad cues). Based on the Motivation-Opportunity-Ability model of information processing, we focus on legibility as an important but underexplored encoding issue that can enhance consumers’ opportunity to process ads based on visual clarity and lead to perceptual fluency effects. Visual acuity declines with age, so legibility is particularly important for older adults and those with vision loss. In line with recommended accessibility guidelines, we manipulated two advertising design factors believed to impact legibility—color contrast and font style—in the supers of a video advertisement for a pharmaceutical drug and tested the communication outcomes (cognition, persuasion). Across three studies with three different-aged populations, we show that legibility was positively related to awareness of information in the supers and to positive perceptions of the advertisement. In line with accessibility guidelines, legibility was rated the highest for most people in the high-color contrast sans serif font supers. Implications for theory, accessibility and older people, and public policy are discussed.