The Power of Three is the collective power of the Charmed Ones that increases their magical strength. Their spells are more powerful, and it allows them to fight and vanquish upper-level demons and to achieve supernatural feats (such as exorcising the Harbinger) which cannot be achieved by other witches. When they join hands and cast a spell, their hands glow.
In 2018, Marisol began the process of unbinding her daughters' powers before she was murdered. Their powers were activated three months later when all three sisters reunited at Vera Manor but they could not access the Power of Three until they accepted their destiny as witches. Once the sisters all agreed, they used the Power of Three for the first time to vanquish the demon, Taydeus.
An Imposter Demon would later take Marisol's form to trick the Charmed Ones into helping it retrieve the Prism of Souls which was contained inside a mirror. The sisters found it inside a triangular box and used the Power of Three to open the box as well as escape the mirror they were trapped inside of.
A few days later, a shapeshifter went after Mel's girlfriend, Niko Hamada, which forced Mel to alter history in order to protect her. She and her sisters drew the Moirai symbol together, then Macy and Maggie cast the spell, which altered events and everyone's memories but theirs.
A few weeks later, a Shadow Demon started hunting sentinels for the shards of the Scythe of Tartarus, which were being guarded by them. Realizing their mother had the last shard, the sisters lured the demon into a trap and tried to vanquish it with a spell. However, the demon summoned the last shard, which knocked down Mel and disrupted the spell. A mysterious individual intervened and stole the Scythe and the Shadow Demon left.
When the sisters fought the Queen of the Cicada Demons, they used a spell to vanquish her. However, the effect was slow as she was too powerful. Knowing her death was inevitable, she tried to self-destruct to kill everyone. However, Macy managed to kill her with a control panel.
On Christmas Eve, Hunter Caine tried to attack the sisters for wounding him. His half-brother, Parker, came to their rescue and tried to banish his brother to Tartarus. Growing weaker with every attempt, the sisters then grab the staff and cast the spell together, successfully banishing Hunter, but Harry gets accidentally sucked in in the process.
A few days later, the sisters fought Alastair Caine. He had the upper hand at first, until Maggie joined hands with her sisters, and together they generated a powerful shield that held back Alastair's fire. Their combined magic proved stronger than his and started to blow his own power back at him until he teleported away.
In January 2019, the sisters used a spell to expel the demon from Mr. Miranda. The spell didn't work the first time because of the girls' internal conflicts. It was then revealed that the Power of Three doesn't work if the sisters in disorder and not focused on a common goal. When girls decided their conflicts, they have been able fulfill a joint spell.
- Unlike the original series, the Veras had a choice as to whether or not they became the Charmed Ones. The Halliwells did not get that luxury.
- Despite having obtained all of their individual powers, the Charmed Ones were required to accept their destiny as witches in order to access the Power of Three.
- Like the original series, the Power of Three is represented on the front cover of the Book of Shadows with the Triquetra symbol.