Later games based on the Warscape engine tend to have less potential due to limitations to the way the campaign map can be changed. Rome: Total War and Medieval II: Total War are widely regarded as the most versatile and modifications for those games can form 'total-conversions' which transport the player to a whole new universe or era. The amount that can be achieved by a modification varies per game. Many players are content with the experience given by the original games (and the DLCs and expansions) as created by CA, however, many players choose to use modifications which expand, improve or completely change the game content.
Numerous user-made modifications have been created for each of the Total War Series games from the first Medieval: Total War onwards.