Start to roll a board game's ten-sided die — set? (5)
I believe the answer is:
radio
'set?' is the definition.
(radio is a kind of set)
'start to roll a board game's ten' is the wordplay.
'start to' says to take the initial letters.
'a board game's' becomes 'ad' (I can't justify this - if you can you should give a lot more credence to this answer).
'ten' becomes 'io' (IO resembles a0).
The initial letter of 'roll' is 'r'.
'r'+'ad'+'io'='RADIO'
'sided die' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for radio that I've seen before include "Transmitter" , "Broadcasting medium" , "Electronic receiver" , "Receiving device" , "Contact" .)