The Experiment is a single-player game mode in Resident Evil: Umbrella Corps.
Abraham Jackson sends his subordinate, 3A7, to various locations to do his bidding.
The Experiment starts on a stage select menu. Only one stage is initially available and a linear path of stages are unlocked as the most current one is completed, with a few single branching stages.
Each stage has a mission description that which has a first half shown when the stage is unlocked and a second half revealed when the stage is completed, a difficulty rating indicated by the number of star icons, a predetermined weapon loadout, and some stage give decal rewards upon completion. Unlike the rest of the stages, the branching stages and the final stage will rank the player based on completion time and will reward the player with a decal if they get an S rank. Each stage also has its own loading screen message that acts either as gameplay tips or more story.
The mode only features 3A7 as the player character. Each stage consists a specific number of rounds of specific game types such as DNA Hunter or Domination. The difficulty progression is set up to slowly increase and to slowly introduce gameplay concepts such as using melee, fighting special infected, etc.
Branching stages are listed next to the linear stage that unlocks it.