PSIONICS

Psionics in GURPS Warhammer are done using the same rules presented in GURPS Basic Set (pg.165) or using the GURPS Psionic source book.  The following exceptions are listed here.

Unlike the standard psionic power of most other universes, in Warhammer 40k it is slightly different.  In your avereage universe, someone with psionic powers taps into internal, mental power. In the Warhammer 40k Universe the "Psyker", as they are known, use their mental powers to tap into the power of the Warp.  A psyker risks the perils of the warp every time he uses a power.  I have lifted descriptions  from various sources, the main source is from the Warhammer 40k RPG (non-GURPS version).

 

THE WARP

Every day spaceships race through warp space, braving the storms and currents of energy to maintain the fragile Imperium of mankind. Only the most senior functionaries of the Imperium are aware of the true nature of the warp, and even these wise and learned men realise that their understanding is severely limited. The warp is an alternate dimension that coexists with the material universe. Though it is formed from pure energy, it too has its inhabitants; voracious beings who would consume the material universe to feed their hunger.

Some know the warp as the void or the Realm of Chaos, for it is here that the dark gods of Chaos hold their court and exercise their absolute, unbridled power over their innumerable subjects as the whim takes them. Others know it as the Sea of Souls and these perhaps understand it best of all, for every creature in the material universe also has an existence in the warp, a spirit-self or soul. With the death of its physical body, the soul of a mortal creature is cast adrift in the limitless sea of energy. Eventually the souls of all but the strongest are drawn to the Chaos gods to feed their lusts. There are points where the material universe and the warp cross over, giving the daemons access to the mortal world, but most are well known physical locations like the Eye of Terror. Far more insidious are the embryonic gateways that lurk in the minds of every psyker.

 

PSYKERS

The souls of mortal creatures stir currents and waves in the energies of the warp. A few, the very strongest, can draw energy from the warp into the material universe. With experience they can give form and purpose to the raw power of the warp, reading minds, sending mental images or messages, locating people or objects, seeing into the future or the past and so on. These psykers are often trained by the Imperium to serve mankind in a myriad of ways. Some become Astropaths who speak between the stars, others fuel the great beacon of the Astronomican, others are granted the honour of sacrificing their souls to the Emperor.

With further training or greater experience, the strongest psykers can wield the energy of the warp in ever more potent ways. They can transport creatures at will, or project their image to give a false position of their location. Psykers such as these serve the military forces and support ordinary troops on the battlefield with their extraordinary abilities.

Even the strongest psyker is at risk from the daemonic entities in the warp. Just as a psyker can draw energy from the warp into the material universe so he can draw daemons too. Sometimes the power of Chaos corrupts the psyker gradually, tainting his mind with alien ideas and motivations. Sometimes a daemon is strong enough to possess a psyker's body and launch itself screaming with triumph into the material universe to wreak havoc.

Repeated Attempts

On page 166 of the GURPS Basic Set is listed the rule for "repeated attempts", this rule will work slightly differently in W40kGURPS.  Everytime a Repeated Attempt is made to access the power of the Warp the Psykers mental discipline is tested.  Every time he fails his "repeated attempt" there is a chance that something terible happens, or it may mean (depending on skill level) that he has just failed his attempt.  A wise, well trianed Psyker can avoid the corruption of the Warp fairly easily, but a reckless Psyker has an increasing chance of being corrupted or summoning a daemon.

Psykers use the power of the warp to cast psychic powers. There are no magic points associated with psykers or psychic powers, it is how mentally adept a psyker is at manipulating the psychic energy that is important. Using high level psychic powers can be dangerous as the energy used for such an ability lights up the warp like a beacon, attracting the hungry daemons towards the source of the power. Even failing to use a low level psychic power might attract a daemon to the psyker's presence. 

As the character increases in mental competence and mastery, his manipulation of the warp becomes much easier and he can use many powers without the risk of daemonic possession. However, even a high level psyker is not safe from the perils of the warp should he fail to cast a powerful psychic ability.

 

Failing a Repeated Attempt 

Everytime a character fails a repeated attempt, roll 3D and consult the table below.  These effects are in addition to any listed affect in the GURPS Psionic source you are using;

00-07Psyker could not concentrate properly due to outside distractions. Skill just fails as normal.
08-11Psyker has encountered some particularly difficult currents of warp energy. Character may try again next round but with an additional -1 penalty to the Repeated Attempt test of skills.
12-13Psyker suffers from a minor flux in the warp. Character is unable to use his psychic powers for another 1Dx10 minutes.
14Psyker suffers from a strong flux in the warp which makes it impossible for the character to use any psychic power for D6 hours.
15Psyker experiences a major flux in the warp as some daemons weaken the character's link to the warp. This makes it impossible for the psyker to use any psychic powers for 2D+12 hours.
16The psyker's soul is found by daemons in the Eye of Terror. They gibber and laugh at him as they wrestle with his soul. As a result the character cannot use any psychic powers for D6 days and must pass a test of skill at the end of that duration or permanently lose one random psychic power.
17The psyker completely underestimates a particularly strong current of warp energy and is consumed by it. The psyker is not killed but is trapped in the warp for 1D days. After that time has elapsed, he returns to the material world 1D miles away from his original location. After this experience the psyker must pass a test of skill or gain the disadvantage Jinxed disadvantage (pg.98, CI).  Each failure increases the Jinx level by 1.  If character already has max Jinx disadvantage, then he must pass a test of skill or lose 1 point of IQ and Fatigue permanently.
18The psyker's (mis)use of the psychic power lights up the warp like a beacon. Daemons of Chaos, and other hideous entities, flock to this sudden tear in reality where they gleefully grasp the terrified psyker and pull him into the warp and his spirit is consumed. At the GM's discretion, the daemon may possess the psyker instead.

 

PSYCHIC POWERS

To learn a psychic power, it is advisable to find a tutor.   This won't be a problem for Adeptus Psykers or the equivalent, but for Renegade Psykers it will be very difficult to find someone willing to teach them. In this case it is likely that the psyker will try to concentrate on a new power, spending days trying to hone the skill. This is not without great risks: the psyker could be tried for witchcraft and burnt at the stake, if lucky, they could be visited by the Inquisition, or worse, if a daemon of the warp discovers the fledgling psyker

It is assumed that anyone with Psionic powers is a part of the Adeptus Psyker and must take atleast one level of Military Rank (pg.CI29 ) per Psionic Power (or Psi School) in addition to any known psionic ability, except Astropath.  Renegade Psykers do not need to take a Military Rank but must alternately take Unusual Background (pg.B23) and suffer a +1 to the "Failing a repeated attempt" table roll (above).  This is considered a 5 point disadvantage.

PSYCHOKINESIS: Hazerarch                                                                                                    *4 Enveloping an object with a layer of crackling power, this ability turns any mundane melee weapon into its power weapon equivalent.  Any "ancient" hand-to-hand weapon can be converted in this way.   Converted weapons add a die (1d) to there damage capability for each + they originally had.  Example a Power Pick would be sw+1d.  Each level of this skill adds 1/2 damage to the total inflicted (so you need atleast 2 levels ABOVE the initial level to add another +1 damage). 

PSYCHOKINESIS: Smite                                                                                                            *4 Striking their foe with holy vengence, the Psyker uses his mind to physically strike an enemy within 50m. The target does not have to be within line of sight but the casting psyker must know that there is a target there, such as using a Scanner.  The attack is performed as the the swing or thrust damage of the Psyker, with a bonus of +1 damage per level of this skill.  Smite is very exhausting, and costs double normal fatigue to use it.

ESP: Storm of Destruction                                                                                                         *4 Bathed in coruscating warp energy, the character becomes an almost unstoppable combat master. Storm of Destruction allows the character to re-roll any missed combat roll for each level of this skill per game day.  The character must pass a test of skills for each attempt, a failure does not use up one of his re-rolls but a critical failure uses up ALL re-rolls for the day.  You may re-roll failed Storm of Destruction rolls.

HEALING: Force Surge                                                                                                               *3    The psyker taps into pure warp energy to temporarily increase his physical being. Force Surge lasts for 24 hours and gives the psyker any one of the following: ST+1, IQ+1, DX+1, +1 HT, +1or HP +1D. Multiple castings just nullifies the original casting in favour of the new one.  The affect is passive and lasts 24 hours. 

ANTIPSI: Destroy Daemon                                                                                                          *4 (Inquisitors and Librarians only)                                                                                                        The psyker does battle with any daemon within 40 metres intent on banishing it back to the warp. This is a form of psychic missile so there needs to be line of sight in order for Destroy Daemon to work. The psyker rolls 2D and adds his level in this ability to the result; the daemon rolls D6 and adds its current number of HP  divided by 5 to the result rounding up to the nearest whole number.

If the Psyker's score beats the daemon's score the daemon is instantly destroyed. If the scores are drawn the daemon loses 3D HP/HT. If the psyker's score is lower than the daemon's then the psyker has just failed. If the daemon's score is twice that of the psyker's then the psyker loses D6 -3 HP/HT.

TELEPORTAION: Daemonic Portal                                                                                             *4   Only a mad man would dare tear the fabric of reality and summon a daemon. As soon as the Force is controlled a portal appears just in front of the psyker, the tear linking unreality with reality. To decide the daemon that is summoned roll a 1D: 1-3 Daemonic Servant, 4 Lesser Daemon, 5 Daemon Prince, 6 Greater Daemon. Duration is until the assigned task is completed. Once the type of daemon has been determined the psyker must control it and strike a bargain (Controlling Daemons section hasnt been done yet).