Rust pits players against each other in a harsh, open world environment with the sole goal being to survive. Animals, such as wolves and bears, represent a threat to new players, but the primary danger comes from other players. The player vs player combat is accomplished with bows, melee weapons and craftable guns. Bullets and other projectiles travel via a ballistic trajectory. There are multiple different types of bullets for each gun. Damage is calculated using hit tracking, meaning shots to the head are more damaging than shots to other parts of the body. Weapon attachments, such as holosights, can be used to give players an advantage. In order to survive, the player must craft tools, build bases, and team with other players. Unlike many other sandbox games, Rust only features a multiplayer mode.

Upon starting a new character, the player will have only a rock and a torch, the former of which can be used to cut down trees and break apart stones. In order to survive in the world, the player must gather resources such as wood and stone and use these resources to craft tools, weapons and other gear. The player can gather cloth, food, stone, metal ore, sulfur ore and wood by killing animals, mining rocks and chopping trees. To craft items, players must have all of the required items. Sophisticated items require more materials, alongside cosumables called components; items scattered around the map