Circle Initiative Rules: All players roll D20 at the start, using any spells, feats or skills that would help them. The highest initiative will act first; then go around clockwise if the player ROLLED an odd number, counter-clockwise if they ROLLED an even number.
During any round, the player who has initiative can take one of three actions: Spell, Skills or roll dice
If you choose either of the two non-dice options, that player cannot repeat that action during the initiative sequence.
There is usually a list of monsters or situations, numbered 1 - 20 (or higher).
First round, the player picks (D6, D8 or D10) and rolls. No player can repeat a dice choice in the first sequence.
Once all dice are rolled - repeat this using D8, D12, D20 and rolls during the second sequence.
Again once all dice are rolled repeat with D12 & D20.
Then go to D20, and remain with this dice.
Until you change areas and tables, do not alter this sequencing for any game night.
If the dice roll indicates combat (or other) action, the player who rolled, acts first. There is no initiative, it continues to go around the circle. Wherever the DM sits, the monsters will act at that point in the game in the sequence. When the combat ends, and initiative action happens again, it goes back to the next player in the initiative sequence before combat was begun.
If a monster, especially bosses or unique creatures, have special initiative rules for combat, and they need to roll dice, then everyone roles initiative. Return to the sequence once that combat is over.