Crusader Kings 3 is about to get "30-40% bigger," but Paradox says you can leave performance concerns at the door

New Crusader Kings 3 expansion All Under Heaven makes its vast map dramatically bigger, which is both exciting and terrifying for long-time players. The introduction of China, Japan, and Southeast Asia opens up a whole wealth of possibilities as you navigate dynasties, shogunates, and the wealth of the Silk Road. But that dramatic increase to the size of the playable world also means more back-end calculations, and the worry it might grind the speed of your playthrough to a standstill. Fortunately, despite its recent DLC faux pas, Paradox says it's got things under control.

All Under Heaven has been such a core focus for the Crusader Kings 3 developer that it recently admitted failing to devote enough attention to the much-anticipated Coronations flavor pack. It came out filled with broken systems and quickly found itself with a dismal Steam rating of just 17%. All Under Heaven is Paradox's opportunity to prove that CK3 still deserves to be ranked among the best grand strategy games on PC, and perhaps even elevate it to new heights, but its size comes with performance worries.

"With All Under Heaven included, the game is about 30% to 40% bigger, in the sense of the amount of playable land and playable living characters," the developer's technical lead Joel Hansson explains. In order "to keep the experience as close to CK3 as it is now," the team has been working to reduce the 'simulation tick duration,' or how quickly the game is able to process everything happening in each passing moment.

The introduction of East Asia and Southeast Asia for the incoming DLC was "a larger challenge than any previous expansion we have done for CK3," Hansson says. "In addition to the typical ~20% slowdowns we would see from unoptimized feature additions, we would now also need to deal with a 32% increase in baronies (and rulers) to the game.

"In our simulation, rulers are the smallest building block for moving the world forward; this is also linearly correlated with the amount of work the CPU must perform. This means that just by putting Asia on the map, we have immediately made the game slower by an equal amount of the size increase."

The good news is that recent testing "measured on both low-spec and high-spec machines" suggests the team has managed to get the new build "comparable to the current live version." In fact, the chart shown above (yellow is the existing game, red is with All Under Heaven) suggests that while the early game is a little slower (due to a higher value on the tick rate chart), the updated CK3 actually runs faster in the mid-to-late game.

Elsewhere, Paradox is trying to trim some more fat. One of the best Crusader Kings 3 mods to improve performance is 'Population Control,' which rather cruelly eliminates people if the world gets too full. "We haven't done something exactly like that, but we have tried to combat the underlying issue," Hansson says. "We went and reduced or eliminated a bunch of 'sources' of characters that generate boring, useless, random, or invisible characters that then linger in guest pools, the sidelines of courts of barons and counts, and that take up space and cost performance."

Hansson warns that "results will vary by the world you create and the world the simulation creates around you," so you shouldn't expect a perfect correlation in your own playthrough. If you're particularly curious about the work that went into achieving this, I'd suggest taking a glimpse at the 37-minute video above or perusing the full blog, which goes into staggeringly exhaustive detail.

In closing, Paradox Studio Black does note that it's updating the game's minimum CPU requirements slightly to the Intel i5-750 and AMD FX-4300 with 8GB of RAM. "During the extensive testing that our hardware lab did we could see that older CPUs like the Intel i3-2120, released back in 2011, struggled to behave predictably under heavy load, especially alongside systems with just 6GB of RAM." As such, it says the new baseline should ensure you reach "the stable and predictable performance needed for what Crusader Kings is today, five years after release."

Crusader Kings 3: All Under Heaven launches Tuesday October 28. You can wishlist it here.

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Will you be playing All Under Heaven? Stop by the PCGamesN Discord and tell us what you think of the new DLC's additions.