Editing Warhammer 40,000/7th Edition Tactics/Psychic 101 (section)

== 0: Generating Psychic Powers ==

Like in 6th edition, psychic powers are generated BEFORE the game starts. A given psyker has access to a certain amount of psychic powers and disciplines, depending on his mastery level and faction. Each discipline has 6 numbered powers (from 1 to 6) and a seventh 'Primaris' power.

To generate its psychic powers, a given psyker first chooses how many powers it wants from each psychic discipline known to it, up to a total of its Mastery Level. In other words, a Mastery Level 2 Space Marine Librarian generates two psychic powers, and can choose to generate them from any of the psychic disciplines marked in his Codex entry (discipline access is therefore entry-specific and not based on Mastery Level). 

The psyker then rolls, one by one, for the powers in the disciplines he chose. Each power is numbered, so each die roll indicates one power he knows from the discipline the psyker rolled on. In the case of multiple rolls matching, thus yielding multiple copies of a particular power, re-roll the copy until it doesn't match. If the psyker doesn't like a particular power, it may choose to exchange the rolled power for the Primaris power of that particular discipline; this decision is made immediately after the roll for the power being exchanged. If a psyker generates all its powers from the same psychic discipline, it gets Psychic Focus - it automatically knows the Primaris power of its chosen discipline in addition to its other powers. If at any point the psyker ever gains a power from a different discipline, it loses Psychic Focus.  Once all your psykers are done rolling for powers, you're set.

The odds of a psyker of a given Mastery Level (ML) being able to guarantee a given power by rolling on the same discipline until it gets it is ML/6, which is slightly better than multiple psykers at lower MLs doing it: for example, an ML2 psyker can guarantee a power with odds 33.33%, while two ML1 psykers both trying for it will manage it (on at least one of them) with odds 30.56%.

*'''Notes:'''
**The decision to exchange a power for a primaris power is done immediately after you roll the die to generate a power. You don't roll for all your powers and then choose to exchange one or more into primaris powers. Make the choice on which table to roll separately for each power you generate - so if you luck out on the first roll, you're perfectly valid in picking a power from a different discipline. 
**A psyker may not know multiple copies of the same power; should you roll the same power multiple times for the same psyker while generating powers, you'll simply reroll the 'extra' copies in the same discipline until you end up with different powers. It is, however, entirely possible for multiple different psykers to know the same power.
**Psykers with a Mark of Chaos or psykers that are Daemons of a particular Chaos God instead automatically know the primaris power of their chosen deity, regardless of the other powers they might generate.
**A psyker who has a force weapon of any description automatically also has the Force psychic power to actually activate the weapon. This does NOT count as one of his mastery level picks, nor does it prevent him from getting Psychic Focus.
**A psyker who has fixed powers of no discipline ''([[Ezekiel]]'s Mind Worm / Ahazra Redth's Mirage)'' does not count these towards psychic focus so long as he generates any remaining powers from a single discipline. This stops them from losing out on Psychic Focus just by having a pre-set power.
**Some psykers - like most Grey Knight units, Eldar Hemlocks and so on - know only predetermined set of psychic powers. Unless otherwise mentioned, these are the ONLY powers they know, they do NOT generate additional ones, and are NOT eligible for Psychic Focus.
**Unlike in previous editions, a psyker's potential power selection is NOT limited by his mastery level. That is, a Mastery Level 1 psyker knows generally speaking one power, but that power may well be Warp Charge 2 or 3 - though a low-level psyker with high-charge powers will have to rely even more on luck of the dice and other psykers in his army to produce enough dice for casting.