You are witches and the world is dangerous for you. Draw a five pointed star for protection: the points are earth, fire, water, air, and spirit.
Fire: fight
Earth: protect
Air: escape
Water: heal
Spirit: change the world at a cost
Assign one die to each element to indicate your power: d4 d6 d6 d8 d10.
Someone plays the Enemy - overzealous puritans, rival magicians, literal monsters, etc. Decide what it wants and how it operates. Each witch uses a d20 to count down their health - the Enemy gets two because the world’s cruel like that.
The Enemy attacks a witch and the target says how they react and rolls the appropriate die. The Enemy’s rolls a die one step up. Highest wins and takes that much health from the loser.
Everyone else can act: protect or heal your ally, attack the Enemy, whatever. Roll the element and add or subtract half your roll as appropriate (round down). If a witch’s roll comes up 1, the spell doesn’t work.
If you hit with Spirit, the enemy rerolls at one die step lower but you subtract 3 from your next roll.
Play continues until the Enemy or the coven is defeated.
Sit in a circle with like-minded people surrounded by the tools of your craft as you work together to do something magical. When you think about it tabletop games are already a little bit like witchcraft. The Spirit mechanic is my nod to the Rule of Three.