The first Assassin's Creed game originally had a co-op mode before it was cut, according to developer Phillipe Bergeron.
The latest release in the series, Assassin's Creed 3, included a co-op Wolfpack mode that players could try out separate to the main campaign.
However Bergeron said that co-op had been planned long before that, as far back as 2007 with the first Assassin's Creed.
"Before we knew about the Desmond story and Animus link, we had a huge co-op component in there," he told OXM.
"But it just became too hard to do: the engine couldn't support it, and then the metaphor we had above it didn't support it. Co-op was one of those big things at the beginning that just didn't make sense in the end."
Bergeron added that co-op didn't fit into the storyline of experiencing an ancestor's memories.
"Your ancestor lived life in a certain way, so assuming you had branching storylines, it creates a paradox. It didn't fit."
The latest DLC for Assassin's Creed 3, The Tyranny of King Washington, is coming out later this month.