A new pathology has just appeared! Patient Zero has been identified, and it's up to you to find the antidote as soon as possible to save the patient and humanity!

Save Patient Zero pits two labs against each other. Each lab employs one or two scientists (i.e., players), while another player plays a lab computer named Savvy. The labs compete to identify an antidote of three molecules, with the labs typically sharing no information with one another; whichever lab finds the antidote first wins.

The general idea of the game is to use lab tools in the best sequence possible to identify the three molecules out of 25 that make up the antidote. (These 25 molecules are arranged in a 5x5 grid on each lab's worksheet.) At the start of the game, Savvy looks at the top three molecule cards in that deck, then sets them aside. These are the molecules the labs must identify. On a turn, each lab submits a tool card to Savvy to show what they want to do in the round, and whichever lab submits first takes its action first in that round. Actions include:

Samply: Draw three sample cards from your lab's deck, and give them to Savvy. Each sample card depicts five molecules, and Savvy will identify which of them show at least one molecule used in the antidote.
Mikroskopo: Choose two cards from your lab's deck, and give them to Savvy, who will treat them like the cards in "Samply".
Dedukto: Receive five molecule cards from Savvy. You (but not the other lab) now know these molecules are not in the antidote.
Centrofugo: Place your centrifuge on your lab worksheet so that it points to four molecules. Savvy then indicates whether any of these molecules are in the antidote.
Scanpad: Place a cardboard device on your worksheet to highlight six molecules in a 2x3 grid. Savvy then indicates how many molecules highlighted (0-3) are part of the antidote.
Spionado: Savvy takes two lab cards from the opposing lab that do not have any molecules in the antidote on them, then shows them to you.
Antidote: Circle three molecules on your worksheet. If all three are in the antidote, you win! If not, Savvy will indicate how many of the circled molecules are in the antidote.

Each lab has a limited number of actions in its deck — eighteen total, with three Samply, two Dedukto, one Scanpad, two Antidote, etc. — so use them wisely, especially the Antidote because if you fail to identify the correct three molecules a second time, then your lab loses the game automatically.

To play Save Patient Zero as a two-player game, each lab draws three molecule cards from the deck, and the opposing lab must identify these three molecules before you can identify the three molecules they drew. Each lab takes the role of Savvy for the opposing lab.