Every run feeds your lineage. Earn XP and levels, spend points across a three-branch skill tree, upgrade the Petri Lab, load run modifiers and chase hundreds of challenges, while new mechanics arrive one level at a time.
Level up
Every Infect Game Mode run earns XP for your lineage. XP raises your level, and each level pays out skill points for the skill tree. Every virus in the lineage shares the same level and tree.
A finished Infect Game Mode run pays 1 XP per 3 kills, 8 XP per room and 150 XP for a victory.
Every completed challenge also pays XP when you collect its reward.
Levels come quickly at first and get steadily steeper: going from level L to L+1 costs 60 + 20L + 4L² XP.
Each level gives skill points: 1 per level, 2 from level 10, 3 from level 25 and 4 from level 40.
Challenges add skill points on top of levelling: Elite challenges pay 1 point, Legendary ones 2, and 16 organ-progress challenges pay 32 more in total.
These milestone challenges pay extra skill points on top of their normal reward.
Refund every skill point in the tree for RNA: 1 RNA per 5 points spent, rounded up (minimum 1).
Every virus your lineage becomes shares one level, one skill tree, one Petri Lab, one gear bag and one record of reached organs.
Each finished Infect Game Mode run ends a generation and adds it to your lineage; deeper unlocks need more finished generations.
Skill tree
One tree of 69 nodes in three branches. Each branch has a root, rows of two nodes, a keystone capstone row at row 5 and a final capstone row at row 12. Every row opens at a set level, lineage length and (for the deep rows) furthest organ reached.
Copy faster than antibodies can keep up: damage, fire rate, crits, extra projectiles and pierce.
Spread fast, strike unseen: speed, dash, stealth, ambush damage and ultimate charge.
Endure, recover, come back stronger: health, regeneration, armor, healing and extra chances.
Circles are stat increases, hexagons are passive effects, squares are active skills for the SKILL button, and diamonds are capstones.
A node needs the node above it in its column; capstone rows need either node of the row before, and the row after a capstone needs either capstone.
The branch's single starting node.
Two nodes that branch off the root.
Opens once your lineage has finished a generation.
Holds each branch's active skill.
The first capstone row: a trait capstone or a mechanic capstone, 3 ranks each.
The deep half of the tree grows with how far into the host you have reached.
Second deep row.
Third deep row.
Fourth deep row.
Fifth deep row.
Last row before the final capstones.
The deepest capstones: elite trait versions and the strongest mechanics.
Three active skills, one per branch, each fired from its own SKILL button; ranks make them stronger (+35% per rank) and recharge 12% faster per rank.
Hexagon nodes add always-on procs; nodes with the same proc add their values together.
Skill tree · Branch 1
Copy faster than antibodies can keep up. Values below are per rank; the maximum is shown in the details. Capstones are in their own section.
+5% damage per rank.
Fire 5% faster per rank.
+4% critical hit chance per rank.
The first hit on each cell deals +25% damage per rank.
+1 projectile per shot.
Blast every cell near you and knock them back.
+15% damage per rank to cells under 30% health.
+4% damage per rank.
Shots pierce +1 cell per rank.
Kills burst, dealing 40% of your damage around them per rank.
+3% critical hit chance per rank.
+10% projectile speed per rank.
Fire 4% faster per rank.
+12% damage per rank to cells under 30% health.
The first hit on each cell deals +20% damage per rank.
+5% damage per rank.
+1 projectile per shot.
Ultimate charges 12% faster per rank.
+4% critical hit chance per rank.
Skill tree · Branch 2
Spread fast, strike unseen. Values below are per rank; the maximum is shown in the details. Capstones are in their own section.
+4% move speed per rank.
Dash recharges 10% faster per rank.
Detection rises 8% slower per rank.
+15% ambush damage per rank.
Kills burst, dealing 60% of your damage around them per rank.
Turn to mist: untouchable and 60% faster for a few seconds.
Ultimate charges 15% faster per rank.
+3% move speed per rank.
Pick up drops from 20% farther per rank.
Detection rises 6% slower per rank.
+12% ambush damage per rank.
Dash recharges 8% faster per rank.
+15% RNA strand chance per rank.
+8% projectile speed per rank.
Kills burst, dealing 30% of your damage around them per rank.
+3% move speed per rank.
+6% nucleotides from cells per rank.
Ultimate charges 12% faster per rank.
Detection rises 6% slower per rank.
Skill tree · Branch 3
Endure, recover, come back stronger. Values below are per rank; the maximum is shown in the details. Capstones are in their own section.
+8 max HP per rank.
Regenerate 0.4 HP per second per rank.
+6% nucleotides from cells per rank.
Heal 25% more after each cleared room, per rank.
When hit, release a shockwave for 120% of your damage per rank.
Heal a share of your HP and take half damage for 4 seconds.
Once per run, survive a lethal hit with 30% HP.
+10 max HP per rank.
Take 3% less damage per rank.
Regenerate 0.3 HP per second per rank.
Heal 15% more after each cleared room, per rank.
Cells that touch you take 8 damage per rank.
Heal 1 HP per kill per rank.
Enter each room behind a shield that blocks one hit.
+5% nucleotides from cells per rank.
+12 max HP per rank.
Take 3% less damage per rank.
Once per run, survive a lethal hit with 20% HP per rank.
When hit, release a shockwave for 80% of your damage per rank.
Skill tree · Capstones
Each branch has two capstone rows. Keystone capstones (row 5) cost 3 points per rank and open at level 15 with 6 generations. Final capstones (row 12) cost 5 points per rank and open at level 50 with 20 generations and the Brain reached. Every capstone has 3 ranks.
Start every run with the Pyrogenic Fever trait already taken (shots set cells burning).
Every few volleys, also fire a ring of 10 bolts in every direction.
Start every run with the Lytic Burst trait at an elite tier (shots burst on impact).
Critical hits arc lightning to nearby cells for 60% of the damage.
Start every run with the Cold Adaptation trait already taken (shots can slow cells).
Every dash drops virion mines that burst when a cell touches them.
Start every run with the Cell-to-Cell Spread trait at an elite tier (shots jump to more cells).
Keep moving to build up speed and damage; it fades when you stop.
Start every run with the Stolen Membrane trait already taken (a recharging shield).
Dropping below 30% HP wraps you in a cocoon that nothing can touch, once per room.
Start every run with the Glycan Armor trait at an elite tier (regrowing armor).
Once in every organ, survive a lethal hit and come back with a burst.
Petri Lab
Spend nucleotides on permanent upgrades in three sections: Core Genome, Signature Ability and Ultimate. Opens at level 2. The core upgrades and the two ultimate radius and charge upgrades are shared by every virus; the rest only count while your lineage is that virus.
Each upgrade has its base levels, then 10 bonus levels at a gentler rate, then two hidden mastery tiers of 10 levels each.
Most upgrades unlock a special effect every 5 levels, with a major one every 10.
Advanced upgrades need 1 to 3 RNA strands to unlock, and every third level of any upgrade also costs RNA.
+12 starting HP per level for 10 levels, then +6 HP per bonus level.
+8% damage per level for 10 levels, then +4% per bonus level.
+5% move speed per level for 6 levels, then +2% per bonus level.
+6% fire rate per level for 8 levels, then +2.5% per bonus level.
+12% dash distance per level for 5 levels, then +4% per bonus level.
+20% ultimate radius per level for 3 levels, then +6% per bonus level. Named Pandemic Reach, Surge Reach, Hemorrhage Reach or Super-spreading Reach depending on the virus.
Ultimate charges 15% faster per level for 3 levels, then 5% per bonus level. Named Viral Shedding, Rapid Transcription, Viral Bloom or Aerosol Load depending on the virus.
Shots mutate 0.4s sooner per level for 4 levels, then 0.1s per bonus level.
Antigenic Shift fires +4 bolts per level for 3 levels, then +2 per bonus level.
Piercing shots pass through +1 more cell per level for 2 levels; bonus levels add +1 pierce every 3 levels.
Infection lasts +2s and burns +3/s per level for 2 levels; bonus levels add +0.5s and +1/s.
Infected cells pass the infection on when they die; bonus levels make it burn +1/s.
Store +1 more cell for Integration Surge per level for 3 levels; bonus levels add +1 stored cell every 3 levels.
Latency lasts +1s per level for 3 levels, then +0.4s per bonus level.
Allies fight +5s longer per level for 3 levels, then +2s per bonus level.
Allies explode when their time runs out; bonus levels make allies fight +1.5s longer.
Integration Surge deals +50% damage to bosses per level for 2 levels, then +15% per bonus level.
Integration Surge allies stay until the room is cleared; bonus levels make the ultimate charge 4% faster.
+5% bleed chance per level for 3 levels, then +1% per bonus level.
Bleeding deals +15% damage per level for 3 levels, then +4% per bonus level.
Hemorrhage reaches +15% farther per level for 3 levels, then +4% per bonus level.
Bleeding deals +30% damage.
Spike volleys fire one shot sooner per level.
Variant Surge lasts +1s per level for 3 levels, then +0.3s per bonus level.
Detection rises 5% slower per level for 3 levels, then 1% per bonus level.
Detection rises a further 15% slower.
Run modifiers
Open at level 8. Craft one-run modifiers with nucleotides and materials, then load up to 3 (one of each) before a run. Each run in any Game Mode uses up one of each loaded modifier, which stays loaded while you have more. Every modifier has an upside and a drawback.
Crafted modifiers go into your stock; load up to 3 different ones for the next run.
Modifiers also drop during runs and go straight into your stock.
Detection rises 40% slower, but you get 10% fewer nucleotides.
Immune cells have 20% less HP, but cells move 10% faster.
+50% max HP, but 10% less move speed.
Start with your signature ability and ultimate charged, and the ultimate charges 30% faster; the dash recharges 20% slower.
+60% nucleotides, but cells hit 15% harder.
Elite cells are 2.5× as common and each elite kill heals 8 HP; cells have 10% more HP.
Every organ's full map is revealed and mutation orbs appear 50% more often; Detection rises 20% faster.
+25% damage and +15% fire rate, but 20% less max HP.
Every room cleared without getting hit adds +5% damage for the run (up to +50%); every hit taken loses a stack.
Below 35% HP you deal +50% damage and move 25% faster; clearing rooms heals half as much.
For 1.2s after every dash your shots deal double damage; you fire 10% slower.
1 in 5 nucleotide drops is a jackpot worth 4×, but elite cells are twice as common.
Every kill heals 3 HP, but you lose 1 HP per second while cells are hunting you (never below 1).
Mutation orbs roll much rarer traits; cells have 15% more HP.
Every organ starts with a CRISPR power-up beside you, and they appear 50% more often; CRISPR lasts 3s shorter.
CRISPR lasts 5s longer, but CRISPR power-ups appear 30% less often.
Tumors take double damage and pay out double, but every organ grows a tumor.
Tumors pay out triple, but grow twice as fast and start a stage bigger.
Every organ starts with a random elemental power-up beside you, and they appear twice as often; they wear off 30% sooner.
Elemental power-ups last 50% longer; 10% less max HP.
The Cytokine Storm meter fills 40% slower; Detection rises 15% faster.
The immune system resists your favourite shot half as much; cells move 8% faster.
Killer T cells have 30% less HP; Detection rises 20% faster.
Rival viruses show up twice as often (rich loot); cells hit 10% harder.
Ground hazards slow you 60% less; 8% less damage.
Gear drops 60% more often from elite cells; cells hit 10% harder.
Rooms roll a tier higher, with more boons and more drawbacks; cells have 5% more HP.
The host takes medicine 60% less often; 10% fewer nucleotides.
Start the run with 1 extra life; 15% less max HP.
Key guardian hooks miss twice as often; the dash recharges 10% slower.
Run modifiers
Loading certain modifiers together unlocks a combo bonus on top of their own effects: 17 pairs and 15 trios that fill all three slots. Each combo rolls a tier when it becomes active, and can rarely mutate.
A newly active combo rolls a tier once that adds damage, max HP and nucleotides; unloading and reloading can't reroll it, and the run that uses it clears the roll.
A freshly rolled combo has a 5% chance to mutate into something much stronger.
Viral Snowball stacks go up to +75% damage.
Jackpots hit 1 in 3 drops.
Elite kills heal 20 HP instead of 8.
Dash recharges 35% faster.
Adrenal Hijack kicks in below 50% HP.
Every cell CRISPR cuts heals 2 HP.
Destroying a tumor heals you fully.
Picking up a power-up heals 15 HP.
Mutation orbs appear twice as often.
The storm meter and shot resistance build another 25% slower.
Gear drops another 50% more often.
Start with 1 more extra life.
Ground hazards don't slow you at all.
Killer T cells have another 20% less HP.
The host takes medicine half as often again.
Key guardian hooks miss twice as often again.
+25% nucleotides.
+20% damage and +20% max HP.
+30% nucleotides and jackpots hit 1 in 2 drops.
Kills heal 3 more HP and elite kills heal 25 HP.
Your ultimate charges 50% faster and the dash recharges 30% faster.
Detection rises 40% slower again and the dash recharges 25% faster.
Even rarer mutation orbs, and Viral Snowball stacks go up to +100% damage.
CRISPR appears twice as often and every cut heals 4 HP.
Power-ups last 40% longer and picking one up heals 25 HP.
Tumors pay out 50% more and destroying one heals you fully.
No shot resistance, the storm builds 30% slower and Detection 20% slower.
Elite kills heal 15 HP and gear drops another 50% more often.
Start with 1 more extra life and kills heal 2 more HP.
Hazards don't slow you, guardian hooks never land, and cells hit 10% softer.
Rooms roll yet another tier higher and +30% nucleotides.
Killer T cells have 30% less HP again and the host barely takes medicine.
Challenges
The Challenges screen opens at level 3. It has daily and weekly challenges plus 637 permanent milestone challenges. Finished challenges wait on the Rewards tab until you collect them, one at a time or all at once.
The smallest reward.
Adds Chaperones.
Adds a Rare gear piece.
Adds an Epic gear piece and a skill point.
The biggest reward: a Legendary gear piece and 2 skill points.
Reward gear is a random piece for the virus you're playing, never above the tier your furthest organ allows.
Every day brings one Easy, one Normal and one Hard challenge, picked from the date.
Every week brings one Normal, one Hard and one Elite challenge.
Permanent challenges come in chains: only the next unfinished step shows, and finishing it moves you on.
Challenges
Dailies and weeklies are drawn from these pools, one per difficulty.
One of these is the Easy daily.
One of these is the Normal daily.
One of these is the Hard daily.
One of these is the Normal weekly.
One of these is the Hard weekly.
One of these is the Elite weekly, worth an Epic gear piece and a skill point.
Challenges
637 permanent challenges in 11 groups. Chains climb in difficulty as their targets grow (E = Easy, N = Normal, H = Hard, El = Elite, L = Legendary).
Kills, rooms, flawless fights, elites, ambushes and ability use.
A Hunter, Bane and Extinction chain for every immune cell type, plus host cells.
Organ bosses, key guardians, tumors and boss feats.
Killer T cells, sieges, treatments, Detection and stealth.
Beat the other viruses competing for the host.
Reaching organs, exploring every room and finding special rooms.
Use the organs' own terrain.
Nucleotides, orbs, chests, power-ups, RNA and materials.
Take, stack and collect traits.
Find, forge, enhance and recycle gear.
Runs, wins, Lab levels and skill ranks.
Unlock schedule
A new save isn't buried in systems on run one. Each in-run mechanic unlocks for the whole save when any virus reaches its level (Hosts & Host Traits: 2 finished generations), then is introduced on its own: a NEW MECHANIC UNLOCKED notice the moment it first shows up (right as the organ starts for tumors, room tiers and immune learning), and except for the Cytokine Storm it's guaranteed to appear in that organ. Only one is introduced per run; the rest wait for later runs. Hosts & Host Traits is introduced on the host reveal before you land instead.
The first few cells you kill in a fight can drop an elemental power-up: a few seconds of a big effect. CRISPR, the rarest, makes you invincible.
Trade-off altars, receptor puzzles and event rooms (siege, gamble, harvest, refuge), marked with coloured borders on the minimap.
Cells can come in stronger tiers (green, blue, purple and up) with affixes like Shielded, Swift or Vampiric; they hit harder and drop better loot.
Dormant Virions can drop from tough cells; each one is an extra life.
When Detection fills to 100, elite hunters follow you from room to room until you destroy them.
Most organs grow a tumor that spreads and sends assassins; destroy it for a big reward or it follows you to the next organ.
Each organ gets its own hazards: cilia, vents, clots, fibres, pits and the occasional drop shaft.
Other viruses want this host too; beat a rival for rich loot, or chase it before it escapes and returns stronger.
When Detection stays high, the host may take antivirals, a vaccine booster or interferon. Walk out of the room to escape the dose, or survive it for a reward.
Rooms roll a tier shown as a coloured minimap border; higher tiers carry more boons and more drawbacks.
If your build gets too strong, the storm meter fills and the immune system sends crimson adapted cells that resist your build.
Lean on one shot type and cells start resisting it; the immune level rises with every organ and Killer T pack.
Each host gets a genome of hidden traits, good and bad, revealed when you infect it. Rarer hosts have stronger traits and richer rewards.
Early runs use smaller rooms and shorter fights; they grow to full size as your best level nears 12 and your lineage nears 6 generations.
Unlock schedule
The main menu starts with just Infect a Host and grows one feature at a time, showing only the next locked one as a teaser and tagging new ones NEW. Level and lineage milestones also widen what runs can offer.
Both menus open once you finish your first run.
The Shift (signature ability) button appears after your first finished run.
Opens after your first run if you found gear, otherwise after your second.
The ultimate button appears after your second finished run.
Burning, poison, chill and shock traits can be offered in runs.
The permanent upgrade lab opens.
The Challenges and Store menus open.
Skip ahead to any organ you've already reached, drafting 6 head-start traits however deep you start.
Bursting, chaining, bouncing, returning and orbiting shots join the trait pool.
Mutations that turn your lineage into Retrovirus can be offered.
Story mode: infect the world city by city; more of the map opens as you level up.
Lineage offers can include mixed boon/curse strains.
Endless waves in the deepest organ you've reached.
Traits can roll purple (Epic) tier; before this they top out at Rare.
Craft and load one-run modifiers with trade-offs, mechanics and combos.
Mutations that turn your lineage into Halovirus can be offered.
Lineage offers can include curses that pay out bigger rewards.
Stolen Membrane shields, Glycan Armor and the Incubation Period extra life join the trait pool.
The strongest boons can be offered.
Traits can roll orange and red tier, up to Prismatic.
Mutations that turn your lineage into Filovirus can be offered.
Pandemic Game Mode continents open by best level and finished generations.
Reached organs
Your lineage remembers the deepest organ it has reached. Reaching a new organ for the first time opens deeper skill rows, better gear and, for three of the viruses, a permanent adaptation announced as '<VIRUS> ADAPTS'. Adaptations stack and apply in every organ and every Game Mode once reached. Influenza A has none.
The deepest organ reached opens new starting points, skill rows and gear tiers.
Captured cells hit 25% harder and take 20% less damage.
Captured cells +10% damage and +15% health; every cell your shots kill adds a kamikaze.
Captured cells +60% damage and +60% health; Latency and Integration Surge hit 80% harder.
Captured cells double damage and health; Latency and Integration Surge hit 120% harder.
Bleeds, Hemorrhage and Viral Hemorrhage hit 80% harder.
Bleeds, Hemorrhage and Viral Hemorrhage hit 50% harder, and bleeding cells deal 35% less damage.
Bleeding +10%, and Hemorrhage weakens cells 5% more.
Infection, spike volleys, outbreaks and the ultimate hit 80% harder.
Spike volleys +15% damage; the Fury variant gives +65% damage instead of +60%.
Infection, spike volleys, outbreaks and the ultimate hit 60% harder.
Infection, spike volleys, outbreaks and the ultimate hit 90% harder.
Resources
Nucleotides pay for most things; RNA and Ribozyme Cores are rare drops tied to Pandemic Game Mode and Endless Game Mode.
The most common base: about 35% of nucleotide drops.
About 30% of nucleotide drops.
About 22% of nucleotide drops.
The scarcest base: only about 13% of nucleotide drops.
Nucleotide piles drop from every cell you kill, plus chests, challenges, Endless Game Mode sets and dismantled gear.
A rare purple drop that unlocks advanced Lab upgrades, pays for every third Lab level and buys skill tree respecs.
The common enhancement material; every enhancement level needs some.
The uncommon enhancement material.
The rare enhancement material, needed to enhance gear from +3 up to +10.
Each enhancement level from +1 to +10 costs more materials, scaled up for rarer and higher-level gear.
A golden ancient retrovirus fragment that a solved receptor puzzle sometimes releases.
Next up
Each run is a generation: strains, legacies, host genomes and animal hosts.
