The Lost Wild will make dinosaur behaviour central to its survival gameplay, with each species designed to react differently to the player, tools and environmental conditions. Game director Gary Napper, formerly lead designer on Alien: Isolation, says the aim is to create tension through believable animal behaviour rather than conventional stealth-game interfaces, making encounters unpredictable but understandable.

Napper highlighted the allosaurus as particularly erratic and aggressive, citing fossil evidence of its teeth embedded in rocks and logs as well as other animals. Players may sometimes need to avoid provoking dinosaurs rather than simply remain unseen, with factors such as nests, feeding, recent hunts, light, weather and time of day affecting behaviour; the game will communicate these moods through in-world visual cues rather than obvious UI prompts.