
Earlier this week, Warhammer Community dropped a helping of new Necron rules and units on us. Nothing in there stirred the internet pot as much as the new Necron Reanimation Protocols. Based on a cursory reading, many posters believed that Rules-As-Written, Necrons just kept rolling their reanimation dice until everything got back into play. Others thought that you got to test for every destroyed model in a unit. In the end, they believed Necron units had to be completely wiped out or they would return nearly complete.
I’ve quoted the text of the Protocols below in their entirety. Give it a read. You’ll want your own mental impression before I begin dissecting the rule.

Ready? Let’s begin
START REANIMATION PROTOCOLS

The first paragraph tells us when to enact Reanimation Protocols. Check immediately after an enemy unit fights or shoots a unit with Protocols. If that unit was not wiped out and had models destroyed by the attacks, then Reanimation Protocols activate.
Please note that “those destroyed models begin to reassemble”. Models from previous attacks, even in the same turn, do not reassemble. Also, “Each time an enemy unit…” indicates Reanimation protocols are checked after each consecutive unit strikes.

Next, total the wounds of the models counting as destroyed in the previous step. Roll that many D6 with a target of 5+. Successful dice rolls are put into a pool. The last sentence merely limits how much the roll may be moddified, never better than 4+ or worse than 6+.

Now we’re comparing the pool to the destroyed models. If you have the same or more dice in the pool than the Wounds characteristic of any of the reassembling models, then you may choose a model to put back into play.
The returning model sets back up with its unit at full Wounds. Normally, you’ll be able to set it up anywhere it could be legally placed. The first two bullet points prevent you from playing shenanigans with the Fight Phase. Reanimating models cannot get into Engagement Range unless the unit is already there. And if you charged this phase, then you can’t get closer to the target of the charge.
Bonus bullet point, the reanimating model does not count as a casualty for Morale this turn.

On to the last paragraph! Remove a number of dice from the pool equal to the Wounds of the reanimated model. The phrase “repeat this process” starts a loop beginning from the previous paragraph. Check again to see if there are remaining “successful dice in the pool equal to or greater than the Wounds characteristic of any of the reassembling models”. If so, then you’ll get to reanimate another model.
If you don’t have enough dice left or run out of models to reassemble, then the loop ends. Any models that failed to reassemble are discarded as are any dice remaining.
END REANIMATION PROTOCOLS
Here are some examples to walk you through the rules interpretations.
Example 1
A unit of 5 Ophydian Destroyers loses 2 models in the shooting phase. The Necron player takes 6 dice, 3 models at 3 Wounds each, and rolls 2, 2, 3, 4, 5, and 6. He places the 2 dice that rolled 5+ aside. Each reanimating Ophydian has 3 Wounds. Since 2 dice is less than 3 Wounds they may not place a model back onto the board. Since the pool has less dice in it than the Wounds characteristic of the destroyed models, the dice and models are discarded. The unit has 3 models now.
Example 2
A unit of 20 Necron Warriors loses 12 models in the fight phase. The Necron player rolls 12 dice and scores 1, 2, 2, 3, 3, 5, 5, 5, 5, 6, 6,and 6. Those 7 dice form a pool. Each Warrior has one Wound, so 7 is greater than 1 and a single model is put back into play. The remaining 6 dice are compared to 1 Wound and are greater, so a second model is reanimated. Likewise, this repeats, removing one die each time until both the models and pool have been depleted. The Warriors unit reanimated 7 models and stands 15 strong.
Example 3
Let’s go back to Example 1. In this case the player rolled 1, 3, 5, 5, 5, and 6. There are 4 successful dice in the pool. The player reanimates an Ophydian. Then 3 dice are removed from the pool. The remaining 1 die is less than the 3 Wounds of an Ophydian, so both the single die and remaining model are discarded. The unit has 4 Destroyers.
Hopefully, the new rule makes a bit more sense. Barring some impressive rolls, entire units of Necrons will not be getting back up. But you will be seeing many, many rolls. Particularly as reanimation triggers after every distinct unit attacks. Shoot a unit with three different units? That triggers Reanimation Protocols at least twice and maybe a third time if the Necron unit is still there. Follow-up some shooting with a charge? They trigger again.
Fortunately for non-Necrons, multi-Wound models will have a much harder time reanimating than single wound models. You’ll often be leaving successful die rolls or destroyed models behind. Necrons will have to work to get their bonus to Reanimation Protocols to maximize their reassembling models. Opponents are going to want to see how negative modifiers are applied to Necrons, getting in a -1 will be very important for making them stay down.
Also, and this is easily missed, the dice you roll is equal to the Wounds characteristics. An Ophydian Destroyer is worth 3 dice whether it was a 3 Wounds or just 1 when destroyed.
Please let me know if you agree or disagree below!