Accessibility: Font size in Storyline 360

Hello LinWong-a312185, 

You are correct. There isn't a specific font size recommendation, but a 12 point is typically the best practice recommendation, which is what we've shared. 

1.4.3 Contrast (Minimum) defines the contrast ratio for text, with an exception for large-scale text and W3C does define this font size as 14pt or 18pt and these are defined as roughly 120% or 150% of the default size for body text, which comes out to 12pt. 

Since you may not be sure what dimensions your learners are viewing your course on, be sure that you are using accessible text and instruct your learners in how to toggle this if needed.