Heal

Heal, also known as Healing, is a terran ability used to heal friendly biological units.

The zerg have the natural ability to regenerate health over time, though the zerg have evolved their own abilities similar to heal, namely Transfusion and Rapid Transfusion, to rapidly regenerate health.

StarCraft
Heal counteracts the stimpack ability, so the use of medics allows the terrans to get the most from s, and even firebats.

All zerg units and structures have the ability to regenerate health over time, though heal does provide excellent support for the zerg.

StarCraft II
In StarCraft II, heal can now be cast at range, increasing its effectiveness. As with the medic from StarCraft, the use of medivac dropships with s and marauders allows the terrans to get the most from stimpacks.

Wings of Liberty
In the Wings of Liberty campaign, the medic returns and is an alternative to the medivac dropship.

Zerg
As with StarCraft. all zerg units and structures have the ability to regenerate health over time, though the queen now has a similar ability to heal known as Transfusion, and heal again provides excellent support for the zerg.

Heart of the Swarm
In the Heart of the Swarm campaign, the swarm queen has a variant of Transfusion known as Rapid Transfusion.