What does the cryptic crossword clue "Mock man with bag in a mess in indoor game (10)" mean?

The definition is "game". The wordplay uses an anagram. anagram of MOCK + MAN + BAG = BACKGAMMON; definition: "game" The answer is BACKGAMMON.

Mock man with bag in a mess in indoor game (10)

Daily Mail Cryptic #17032 | 25 Across | 2023-02-13 flower