Rule of board game accessories, including ink (7)
I believe the answer is:
dictate
'rule' is the definition.
(I know that dictate is a more specific form of the action rule)
'board game accessories including ink' is the wordplay.
'board game accessories' becomes 'dice' (I've seen this in another clue).
'including' is an insertion indicator.
'ink' becomes 'tat' (I've seen this in another clue).
'dice' enclosing 'tat' is 'DICTATE'.
'of' acts as a link.
(Other definitions for dictate that I've seen before include "Determine; read out to be taken down" , "Lay down the law" , "Command" , "say" , "Issue commands" .)