Not just the way you deploy and advance your troops across the battlefield, Stratagems are ways you can use points to make your 40k army that much more effective. While there are general ones in the core rulebook, the new Necron codex has 40 new ones specific to the mechanical monstrosities.
From the article:
One of the benefits of sleeping for millions of years is that you get to dream up new ways to defeat your enemies. Now, as the Necrons prepare to reclaim the galaxy, they bring with them a host of tactics to unleash on the younger races who would dare to usurp them. Today, we’re taking a look at some of the Stratagems in their codex.
The new Necrons codex features a whopping 40 Stratagems that can be used in addition to the core ones in Warhammer 40,000 Core Rule Book, and these are split into six different categories. This makes it easier for you to keep track of the different Stratagems and when in game they are used – the same thing is happening to all of Stratagems in the new codexes.