See a tot inside playing a game (5)
I believe the answer is:
lotto
'game' is the definition.
(the UK National Lottery)
'see a tot inside playing a' is the wordplay.
I cannot quite see how this works, but
'see' could be 'lo' (archaic exclamation meaning 'look!') and 'lo' is located in the answer.
an anagram of 'tot' is 'tto' which is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lotto that I've seen before include "National gambling game" , "Bingo-like game" , "gamble" , "Lucky draw" , "Game in which numbers are drawn" .)