- Biomass pickups will now merge together when less than 4 distance apart, up from 1.9.
- Biomass now drops at a base rate of 5 per supply, up from 4 per supply on casual and normal difficulty.
- Biomass now drops at a base rate of 4 per supply, up from 3 per supply on hard difficulty.
- Biomass now drops at a base rate of 2.5 per supply, up from 2 per supply on brutal difficulty.
- Abathur’s Level 3 Talent, Virulent Nests, now allows Toxic Nests to drop 50% additional Biomass, down from 100%.
- Tunneling Claws cost decreased from 150/150 to 100/100.
- Adaptive Plating research cost decreased from 150/150 to 100/100.
- Hydriodic Bile research cost decreased from 150/150 to 100/100.
- Adaptive Plating bonus armor increased from 3 to 6.
- Roaches now gain armor per point of Biomass, up to a maximum of 5 additional armor with 100 Biomass.
- Biomass picked up by Ravagers will now decrease the cooldown of Corrosive Bile, up to a maximum of 50% at 100 Biomass.
- Ravager Corrosive Bile range increased from 9 to 12.
- Symbiote Ability Cooldown Mastery replaced with Symbiote Ability Improvement Mastery. This new Mastery increases the damage dealt and absorbed of Abathur's Symbiote ability by 3.33% per point, up to a maximum of 100%.
- Double Biomass Chance Mastery increased from 0.5% per point to 1% per point. Maximum chance increased from 15% to 30%.
- Abathur's Toxic Nest Damage and Respawn Chance Mastery changed to Toxic Nest Damage Mastery. It now no longer provides Toxic Nests with a chance to respawn.
- Abathur's Level 3 Talent, Virulent Nests, now provides Toxic Nests with a 50% chance to respawn when they die, in addition to its current functionality.
- Mend Heal Over Time changed from 50 health over 15 seconds to 50 health over 10 seconds.
- Mend Healing Mastery replaced with Mend Healing Duration Mastery. Mend Healing Duration Mastery increases the Heal Over Time duration of Mend by 10% per point, up to a maximum of 300%.