Each run lands on a random host behind a big "INFECTED" title, then the run begins underneath it.
Usually a person; about 1 run in 5 lands on one of the setting's animals instead, which joins your Codex Once Hosts & Host Traits are introduced (Generation 2), a host reveal card shows the host before you go in In Pandemic Game Mode the hosts are the chosen city's people and wildlife From the Codex Once your lineage has reached deeper organs, a map of 8 area cards lets you start in any organ you've already reached.
Unlocks with the "Start in deeper areas" milestone (Level 3, Generation 2) Cards read AREA 1 to AREA 8; each shows the organ and its boss, and unreached areas stay greyed out Area 1 (Nasal Passage) is the normal start Backing out of the picker is free: nothing is spent until the run begins From the Codex Beginning a run in an organ you've already reached.
Fun fact: Starting deeper is faster, but you miss the earlier organs' loot and traits.
Starting Deeper in the Codex Starting past the first organ opens a draft: pick 6 traits from a pool of 20 to make up for the skipped organs.
Always 6 picks, however deep you start The pool can repeat a trait; picking it twice stacks it Tier odds in the pool improve the deeper you start The first time you reach an organ, a card announces it as a new starting point From the Codex Beginning a run in an organ you've already reached.
Fun fact: Starting deeper is faster, but you miss the earlier organs' loot and traits.
Starting Deeper in the Codex The first time you meet an enemy, boss, room type, hazard or system, its briefing card pops up and pauses the run (if another panel is already open, a short notice appears instead).
The full briefing (In Game and Real World tabs) stays in the pause menu for the rest of the run Meeting something also unlocks its Codex entry Brand-new saves fight in compact single-screen rooms with one wave; bigger rooms, narrow corridors and longer fights open up as your lineage grows.
Growth follows your best virus's level (full at Level 12) and longest lineage (full at 6 generations) Fight rooms grow from 1 screen of floor up to about 4 screens Fights grow from 1 wave up to 4 waves, and waves fill out from 80% to the full number of cells From the Codex Each organ is a map of connected rooms, different every run.
Fun fact: Bigger rooms hold more cells, spread around the whole room, and always fight in several waves.
Rooms & Waves in the Codex 
