Realism: Invictus is the Beyond the Sword version of the Civilization 4 mod that was formerly known “Total Realism” when it was being developed for Warlords expansion pack of Civilization 4. Our mod has been with Civ since the earliest days; it was, back when it was called just “Realism”, among the first comprehensive modpacks seeking to rebalance the game. For many years now, the mod continues its life and its evolution. For detailed statistics on what the mod adds, please check the features section.
At first, I thought this mod took itself too seriously, what with leader weaknesses and almost complete lack of alternate tech paths. But then I started playing it again. It's the largest mod to not include future-era stuff, which on second examination is a strength because it doesn't overexert itself. Most importantly, Invictus has the deepest combat system of ANY Civ game before or since. If we're lucky, Firaxis takes notes for Civ VI.
And War Elephants. Woe to whoever has to fight them off.