Literary riddles have enjoyed a reputation as valuable teaching tools of grammar, logic and rhetoric since Classical Antiquity. Alongside the typical ambiguity which a good riddle strives to generate through polysemy and metaphor, medieval riddles create further semantic uncertainty through the peculiarities of their handwritten form, such as the use of rare graphemes and inconsistencies in spelling, punctuation, or word separation. This paper traces logogriphs, iconicity, orthographic and syntactic ambiguities in selected Old English riddles and their relevance for the riddling and reading techniques of their contemporary users. It presents an iconic clue for Exeter Book Riddle 23 and a new spectrum of solutions for Riddle 45, revealed here by means of grammatical, logogriphical, and etymological evidence. The latter is used as a case in point to demonstrate the didactic value of riddles in teaching medieval typology and exegesis. It suggests a palaeographical, etymological and, above all, theological reassessment of the riddles written in Old English.