The basic idea of this ruleset is that you place 6 objective markers around the board before the game begins. Then each turn you generate three Vital Objectives from the table, each of which will have a different objective to complete and a different amount of Victory Points awarded. When using this ruleset the normal Victory Conditions are ignored, and instead the player with the most Victory Points at the end is the winner. Some of the Vital Objectives are as simple as capturing Objective Marker 3, while others involve you killing an enemy model with the Hero keyword, or dispelling an enemy spell. You check to see if you have achieved any objectives at the end of your turn, tally up those Victory Points and then discard that Vital Objective. You can also discard up to one other Vital Objective you did not achieve if you wish. This way you are not stuck with an objective for the whole game that you know you won’t be able to achieve. At the start of your next turn if you do not still have three objectives you generate some new ones until you have three active ones. who ever has the most Victory Points at the end of six Battle Rounds wins.
Vital Objectives is part of, the unofficial, The Endless Deserts Tomb Kings battletome supplement for AoS.
Read more about Vital Objectives here and here!