The following ruleset was originally written as an appendix to the generic TO player pack template, developed and shared by Old Town Throw Down. You can see the entire template here.
The purpose of the clock
Full games of Age of Sigmar are expected to finish within the 2.45-hour round time limit.
The purpose of a chess clock is to ensure a full game can be played and encourage speedy resolution of in-game actions. The chess clock is meant to ensure a roughly equal distribution of time between two players. Chess clocks should not be thought of as an easy way to auto-win a game or a way to time your opponent out.
If one player requests a chess clock be used at a table, both players must use and abide by these chess clock rules.
If you do not have a chess clock, approach a TO to request a chess clock for your table.
How to use a chess clock
Below you will find guidelines on how to use a chess clock. In Age of Sigmar, each player takes actions in the other player's turn; therefore, these guidelines should not be thought of as a perfect measure of each player’s time used during a game but rather a way to ensure a roughly equal distribution of time between players.
The clock should be started as soon as the roll to decide attacker and defender is made (i.e. before deployment).
The clock time runs off of the defender’s time as he or she places terrain on the board (but after choice of mysterious terrain and terrain types have been determined [see TERRAIN section above]), time is passed to the attacker as he or she picks sides and makes his or her first deployment. Once all of the models from the attacker's first deployment are placed on the table time is passed to the defender and his or her first deployment is made. Time is then passed back to the attacker. This procedure is alternated until all units are deployed.
If a player is setting up a large unit, the opponent can choose to switch the clock and start setting up their own unit. For example, Player A starts setting up 40 clanrats and starts their clock. After 10 rats are placed, it is obvious where the remaining 30 will go, so player B switches the clock to their time and sets up their own unit. Player A finishes setting up the rats on player B’s time (unless B finishes setup before the 30 are down). Players should be encouraged to take actions simultaneously if possible.
Who takes the first turn is determined by the player who finished deploying first and the clock runs on his or her time while the decision is being made.
During the game
By default, the clock runs off the time of the player who is taking their turn.
During a player’s turn, time is passed to the player not taking their turn when the following scenarios occur.
If the player not taking their turn wishes to use an ability/or reaction command ability during the other player's turn, time is passed to that player while this ability is being resolved and then once resolved time is passed back to the player currently taking their turn.
When the player not taking their turn activates a unit to attack during the combat phase, time is passed to that player then passed back to the player currently taking their turn.
When a player makes a save/ward roll of any kind, time is passed to the player making the save/ward roll.
When a player makes a battleshock roll time is passed to the player making the battleshock roll.
If the player not taking their turn inquiries about the rules of the player of the who is taking their turn army, time is passed to the player not taking their turn until the rules are explained.
However if possible, and if both players agree, either player may take actions whilst another player is also taking an action. For example a player may start rolling their next attack at the same time as their opponent is removing casualties from the previous attack.
A player may always choose to forgo rolling to determine the results of a combat, starting with the player whose turn it is. If they choose to save their time this way, their opponent may decide the results of the combat. This can range from leaving the enemy unit unharmed, up to removing the entire unit involved in the combat. This must be decided before any rolls are made in the combat.
Any major rule dispute results in a paused time scenario. The time is to remain paused until a formal judge is called to the table and resolves the dispute.
If a player’s time runs out, they may not perform any actions except for those listed below. The only exception is if they are in the middle of moving a unit, they may finish so that the unit is placed legally on the board. As an example, this can include moving a unit in the movement phase, finishing moving a unit into combat (note they will not be able to attack), or consolidating a unit. Any other action is immediately stopped. A player who has ran out of time may only perform the following actions:
Making saving throws and taking a battleshock test if required to.
Scoring objectives that they have already achieved or already hold.