Effort
Instead of an action, Bonus Action, Reaction, and movement in combat, you have 3 Effort to spend on your turn. Generally, doing any single thing in combat costs 1 Effort.
Leveled spells with a casting time of 1 action can only be cast once per turn.
You regain all spent Effort at the end of your turn, so there’s no need to save them up. Spend them all on your turn and when you’re done, you get them all back.
Doing simple tasks (opening an unlocked door, dropping an item, ending concentration, etc.) costs no Effort and can be done for free 1/turn.
Speaking or having quick conversation or can be done whenever you want with no cost, even when it is not your turn.
Rushed Attacks
Making more than your normally allowed attacks each turn is allowed (provided you have enough Effort to spend), but these attacks trigger stacking Disadvantage: you’ll roll an additional die and remove the highest result for each stack.
Spells that trigger saving throws can also be rushed; however, instead of stacking Disadvantage for extra saving throw spells, the saving throw is rolled with stacking advantage by the target. Damage from these attacks is unaffected by Disadvantage and ignores enemy armor.