'The return of baby driver': The Dwarf Fortress Siege Update briefly reintroduced an old bug where dwarf babies pilot their moms like mech suits until they die of dehydration because babies don't know what drinking is

On Monday, Dwarf Fortress received its eagerly awaited Siege Update, which revamps Fortress mode sieges by giving invading forces all sorts of dastardly new tools and behaviors to circumvent, demolish, and overrun the player's fortifications. Dwarves, meanwhile, received new toys to stem the tide of besieging goblins, like autocrossbow turret emplacements and metal-fortified walls. Overnight, the fantasy settlement sim has rewritten decades of player defensive strategy.

One of the interesting complications added by the Siege Update, however, is an unintentional one. Shortly after the update went live, players started reporting on the Kitfox Games Discord that, inexplicably, dwarves in their forts were dying of starvation and dehydration. And not just any dwarves: The moms were refusing to eat, and their babies were the culprit.

The problem, you see, is that moms are like horses—in Dwarf Fortress, at least. In DF, mothers always hold their newborn babies until the infants reach an age where they can walk, play, and feed themselves. To achieve that, the game actually uses the same systems that let soldiers ride war mounts: While we're shown a dwarven mother holding her child, Dwarf Fortress essentially considers the baby to be "riding" their mom. It's like a mommy mech situation.

Dwarf Fortress is basically Neon Genesis Evangelion, is what I'm saying.

The Siege Update, as it happens, did some considerable war mount revising, increasing the number of potential war mounts fielded by goblin siege forces and making flying mounts more reliable. In the process, it seems the update accidentally swapped who's in charge of piloting moms: Where dwarven moms typically direct their own pathfinding and job selection, the update made it so the babies were suddenly in the driver's seat.

Unfortunately that spells death for the mom, because babies in Dwarf Fortress—understandably—don't know how to do anything, eating and drinking included. I fired up an old save to confirm it: I watched one of my fortress moms march determinedly towards the task she was pursuing when I'd last saved, and when she got there she just stopped to wait for her inevitable end. The baby was calling the shots, except it doesn't know what shots are, because it's a baby.

What's fascinating, as Dwarf Fortress developer Putnam noted in the Kitfox Discord, is that this exact bug has happened before. In earlier versions of Dwarf Fortress, goblin besiegers who arrived riding amphibious mounts would often end up drowned when their steeds inevitably plunged into waterways during their charge, because the mounts determined their pathfinding instead of the rider.

When a subsequent change left the rider in command of their mount's movement, it meant a safer life for goblin cavalry—until they entered whatever meat grinder the player had built for them, anyway. The rider chooses where to ride, and all is right with the world—unless that world happens to leave mothers fatally "babybrained" by their newborn pilots, just as the Siege update did this week.

"The return of baby driver," pronounced Dwarf Fortress player, modder, and community fixture Rumrusher.

While the repeat of the big baby mistake gave us an opportunity to revisit Dwarf Fortress's long, mesmerizing history of hyperspecific bugs, the moms didn't have to suffer very long. Thanks to Putnam's quick work at diagnosing the issue, a hotfix was deployed this morning to solve the problem. Motherhood is no longer a terminal condition in the mountain halls.

If, for some reason, you'd like to revisit this short-lived period of baby chaos, you're in luck: Dwarf Fortress makes previous versions available as beta branches on Steam. The pre-hotfix Siege Update patch, version 53.01, isn't on the list just yet, but I'd expect to see it there soon.

Now all anyone has to worry about is the troll sappers, the goblin siege engineers, the demonic commanders, and the increased assortment of warbeast reinforcements. Things are looking up!