Complex sentence: In fighting games, combo specifically indicates a timed sequence of moves which produce a cohesive series of hits, each of which leaves the opponent unable or almost unable to block or otherwise avoid the following hits in the sequence.
Split into simpler sentences: In fighting games, combo specifically indicates a timed sequence of moves which produce a cohesive series of hits. This hit is then followed by an often predetermined sequence of other hits, each of which leaves the opponent unable or almost unable to block or otherwise avoid the following hit (s) in the sequence.