GURPS: Psionic Powers with Multiplicative Modifiers

I wondered how point costs change with Multiplicative Modifiers (Powers p. 102), so I decided to calculate the costs for the abilities in Psionic Powers. Here are my findings.

I think my calculations are correct, but I may have some errors (especially for Innate Attack with partial dice). I rounded costs except for openly leveled abilities.

Note that I made no changes to the modifiers and have not repriced any of the techniques.

Anti-Psi

Cancellation, Interruption, Psionic Overload, Psionic Shield costs have no change.

Para-Invisibility

Additive: 5/level

Multiplicative: 4/level

Psychic Armor

Additive: 8/level

Multiplicative: 7.2/level

Screaming

Additive: 9 for level 1; 15/additional level

Multiplicative: 9 for level 1; 4.5/additional level

True Sight

Additive: 16/21

Multiplicative: 13/20

Notes

These costs are mostly the same or slightly lower with Multiplicative Modifiers, but Screaming is significantly less expensive for obvious reasons.

Astral Projection

Astral Armor, Astral Celerity, Astral Sight costs have no change.

Astral Sword

Additive: 8 for level 1; 6/additional level

Multiplicative: 3.725 for level 1; 2.345/additional level

Astral Travel

Additive: 28/36/48/56/68/80

Multiplicative: 36/36/36/36/36/54

Notes

Most of the abilities have identical costs since they don’t have any enhancements. I am not sure if I calculated Astral Sword correctly. Astral Travel’s cost schedule doesn’t work well because of the -80% cap.

Ergokinesis

Cyberpsi

Data Retrieval, I/O Tap and Remote Control costs do not change.

Netrunning

Additive: 20/30/40/50/75/90/100 + 7/additional level

Multiplicative: 32/32/32/32/32/48/64 + 7/additional level

Notes

Netrunning suffers from the same problem as Astral Travel.

Electrokinesis

Dampen and Electric Vision costs do not change.

Confuse

Additive: 15/18/21/26 + 26/additional level

Multiplicative: 6/13/20/24.3 + 24.3/additional level

EK Shield

Additive: 4/level

Multiplicative: 3.6/level

Lightning

Additive: 12/level

Multiplicative: 8.4/level

Radar Sense

Additive: 12 + 2/additional level

Multiplicative: 11/14/16/17.6 + 1.6/additional level

Surge

Additive: 11/level

Multiplicative: 12.4/level

Notes

These prices are close, and the cost schedules all work. Surge costs more due to the -80% limitation limit.

Photokinesis

Flash

Additive: 22 + 5/additional level

Multiplicative: 6.3 + 1/additional level

Hologram

Additive: 10/13/15/18/20/23/25/28/30/33

Multiplicative: 7/7/7/11/12/12/13/14/15/15

Photorefraction

Additive: 5/level; 4/level for blocking variant

Multiplicative: 4.32/level; 3.52/level for blocking variant

Notes

These abilities translate fairly well. Photorefraction is slightly cheaper while Flash is significantly cheaper. Hologram suffers from the -80% limitation restriction problem and a slow cost progression.

ESP

Divination

Combat Sense and Visions costs do not change. Why doesn’t Danger Sense get the PM?

Prognostication

Additive: 18/23/28/33/38/43/48/53/58/63/68/73/78

Multiplicative: 11/12/14/15/17/18/20/21/23/24/26/27/29

Retrocognition

Additive: 14/20/30/40

Multiplicative: 14/19/26/33

Retrocognitive Flashbacks

Additive: 10/16/26/36

Multiplicative: 8/9/12/15

Signature Sniffer

Additive: 4/9/18/28

Multiplicative: 4/9/18/27

Notes

Signature Sniffer has a similar cost, and the other abilities are fairly close at low levels, but high levels tend to cost much less with Multiplicative Modifiers.

Remote Senses

Awareness

Additive: 9 + 2/additional level

Multiplicative: 9/11/13/15/17 + 1.7/additional level

Clairaudience

Additive: 13 + 5/additional level; 5 points with Clairvoyance

Multiplicative: 13/18/23/27.5 + 2.75/level; 5 points with Clairvoyance + 0.5/level beyond 4

Clairvoyance

Additive: 13 + 5/additional level

Multiplicative: 13/18/23/27.5 + 2.75/level

Notes

These costs are similar. Multiplicative Modifiers make purchasing Clairaudience with Clairvoyance inconvenient.

Other Abilities

Seeker Sense cost may or may not change. The individual Detect abilities may cost a little less.

Psi Sense

Additive: 8/13/22/32

Multiplicative: 6/13/21/30

Psidar

Additive: 9/14/19/29

Multiplicative: 6/14/18/27

Psychic Hunches

Additive: 14/29/36/51

Multiplicative: 14/27/25/49

Spirit Communication

Additive: 8/13/18/28

Multiplicative: 8/12/16/24

True Sight

Additive: 15/19

Multiplicative: 11/17

Notes

These prices are slightly lower but still close wiht Multiplicative Modifiers.

Probability Alteration

Combat Sense is the same as the Divination version. Adjustment and Second Chance costs do not change.

Coincidence

Additive: 27/level

Multiplicative: 24/level

Curse

Additive: 22/24/26/28/30/32/34/36/38

Multiplicative: 7/7/8/10/12/12/13/13/14

Weather Control

Additive: 22/level

Multiplicative: 24/level

Notes

Weather control is slightly more expensive due to the -80% limitation cap. Curse costs significantly less. Adjustment simply happens to cost the same due to rounding.

Psychic Healing

Aura Reading

Additive: 4/7/13/16/22

Multiplicative: 8/8/8/8/8

Cure

Additive: 18 + 6/additional level

Multiplicative: 18 + 3.6/additional level

Cure Disease

Additive: 6/level

Multiplicative: 6 + 1.2/level

Cure Injury

Additive: 12 + 6/additional level

Multiplicative: 12 + 2.4/additional level

Disease Shield

Additive: 15/17/19/21/23/25/27/29

Multiplicative: 7/8/8/9/9/10/11/11

Life Extension

Additive: 9 + 12/additional level

Multiplicative: 9 + 7.2/additional level

Sleep

Additive: 25/28/31/36 + 36/additional level

Multiplicative: 8/18/29/34 * 34/additional level

Notes

Aura Reading’s cost is entirely flat. Low levels of Sleep are inexpensive, but the cost rises as the limitations are removed. The others are close but slightly less expensive.

Psychic Vampirism

Drain (Attribute)

Additive: 24/26/28/30/32/34/36/38/40

Multiplicative: 18/19/20/22/23/25/27/28/30

Drain Emotion

Additive: 10/15/25/30

Multiplicative: 17/17/17/17

Steal Dreams

Additive: 23/31/40/48/67

Multiplicative: 12/17/30/35/47

Steal Energy

Additive: 32/34/37/39/42/44 + 7/additional level

Multiplicative: 14/14/14/14/14/14 + 1.92/additional level

Steal Life

Additive: 25 + 4/additional level

Multiplicative: 18 + 2.79/additional level

Steal Power

Additive: 55/65/75/85/95/105/115/125/135

Multiplicative: 20/20/20/25/30/33/36/39/42

Notes

Drain Emotion and Steal Energy are basically flat with Multiplicative Modifiers. Steal Power is much more affordable.

Psychokinesis

Telekinesis

TK Bullet

Additive: 5/level

Multiplicative: 4.48/level

TK Crush

Additive: 5/level

Multiplicative: 3.665625/level

TK Grab

Additive: 7/level; 4/level (Short Ranged)

Multiplicative: 4.75/level; 3.25/level (Short Ranged)

Levitation

Additive: 14 + 2/additional level

Multiplicative: 14 + 1.98/level

Other Abilities

Cryokinesis

Additive: 13/level

Multiplicative: 0.81/level + 0.69/level + 7.7625/level (however you want to round that)

Note that Temperature Control is worth less than the Fatigue Attack when using Multiplicative Multipliers.

PK Shield

Additive: 4/level

Multiplicative: 3.6/level

Pyrokinesis

Additive: 14/level

Multiplicative: 0.81/level + 7.7625/level + 1.5525/level (however you want to round that)

Note that Temperature Control is worth less than the attacks when using Multiplicative Multipliers.

Notes

PK Shield was close. Recomputing the other abilities was a bit of work. This demonstrates the fact that converting abilities that make use of Alternative Abilities may require swapping some abilities.

Telepathy

Communication

The costs for Borrow Skill, Emotion Sense and do not change.

Telereceive

Additive: 21/36/42/45/60/75; 9/18/24/27/42/57 (Shallow)

Multiplicative: 21/36/42/45/55/68 ; 9/18/24/27/41/54 (Shallow)

Telesend

Additive: 9/18/21/24/27/42

Multiplicative: 9/18/21/24/27/41

Telespeak

Additive: 18/30/39/45/63/93

Multiplicative: 17/27/38/44/54/76

Notes

The costs are mostly identical. There are really only differences when enhancements and limitations overlap.

Control

Aspect

Additive: 4/level

Multiplicative: 3.4375/level

Emotion Control

Additive: 10/15/25/30/55/80; 5 points with Suggestion

Multiplicative: 12/12/18/24/34/44; 11 points with Suggestion

Mental Surgery

Additive: 10/25/33/48/65

Multiplicative: 21/26/28/33/38

Mind Swap

Additive: 20/45/60/65/70

Multiplicative: 22/39/55/61/66

Mindwipe

Additive: 20/23/26/31/36/41

Multiplicative: 8/16/24/29/33/38

Sensory Control

Additive: 33/40/43/45/48; 20/28/30/33/35 (Overload)

Multiplicative: 15/30/35/40/45; 10/10/10/15/20 (Overload)

Suggestion

Additive: 10/20/30/35/50/75/100

Multiplicative: 12/12/24/30/43/55

Telecontrol

Additive: 30/45/60/75/90

Multiplicative: 30/30/30/38/60

Notes

Sensory Control (Overload) and Telecontrol have the early flat cost progression. Emotion Control is more expensive with Suggestion, but it still less that with Additive Multipliers except at low levels.

Offense

Instill Fear

Additive: 18 + 3/additional level

Multiplicative: 18/21/24/27 + 2.7/additional level

Mental Blow

Additive: 17/20/23/28/33/38

Multiplicative: 8/15/22/27/31/36

Mental Stab

Additive: 33/43/52/69/85/101

Multiplicative: 27/27/44/58/71/85

Sleep

Same as the Psychic Healing version.

Notes

Costs are fairly similar except that Mental Stab is quite a bit less expensive.

Sense and Defense

Mind Clouding

Additive: 6/level

Multiplicative: 2.75/level + 2.8875/level

Mind Shield

Additive: 4/level; 3/level (Feedback)

Multiplicative: 3.96/level; 2.97/level (Feedback)

Telepathy Sense

Additive: 4/7/11/16

Multiplicative: 3/7/11/15

Telescan

Additive: 11/15/20/25/30

Multiplicative: 7/14/18/22/26

Notes

These prices are fairly close. Mind Clouding and Mind Shield are practically identical except for high levels of Mind Clouding.

Teleportation

Autoteleport

Additive: 20/30/40/50/55/60/65/70/75/80/85/90/95/100

Multiplicative: 32/32/32/32/32/32/32/32/32/32/40/48/56/64

Combat Teleport

Additive: 40; 15 with Autoteleport

Multiplicative: 33; varies between 5 and 8 with Autoteleport

The “custom limitation” should be a limitation for Reliable or Blink.

Exoteleport

Additive: 46 + 5/additional level; 35 + 5/additional level (Touch-Only)

Multiplicative: 52 for levels 1-6 + 0.9/additional level; 16 for levels 1-6 + 0.3/additional level (Touch-Only)

RL Exoteleport

Additive: 45/55/65/75/80/85/90/95/100/105/110/115/120/125; 34/44/54/64 + 5/additional level (Touch-Only)

Multiplicative: 46 for levels 1-8 + 6/additional level; 10.4 for levels 1-8 + 1.2/additional level

Innerportation

Additive: 9/level Multiplicative: 8.352/level

Portersense

Additive: 4/7/11/16

Multiplicative: 3/7/11/15

Notes

Both Auto/ExoTeleport have several levels of equal cost. Both start a little more costly but quickly become much less expensive. As expected, the Touch-Only version are much cheaper. Innerportation and Portersense have nearly identical costs. Combat Teleport has an inconvenient pricing scheme when combined with Autoteleport but is always less expensive with Multiplicative Modifiers.

Additional Powers

Animal Telepathy

Animal Speech

Additive: 15/18/20/25/30/35/40/45/50

Multiplicative: 15/18/20/24/28/32/36/40

Beast Control

Additive: 10/18/23/48/73

Multiplicative: 10/10/13/19/25

Biokinesis

Mold Flesh

Additive: 32/34/36/38/40/42/44/46

Multiplicative: 8 + 0.4/additional level

Strike Sense

Additive: 22/24/28/33 + 33/additional level

Multiplicative: 7/10/20/24 + 24/additional level

Dream Control

Dream Projection

Additive: 20/40/50/60/65/70/75/85/95

Multiplicative: 26/26/26/26/39/46/49/53/62

Reshape Dream

Additive: 7/14/18/25

Multiplicative: 10/10/10/10

Psychometabolism

The costs does not change.

Notes

The Psychometabolism abilities don’t have enhancements, so their costs don’t change. Dream Control has an initial flat cost schedule, and Reshape Dream is entirely flat. Mold Flesh much cheaper and is almost completely flat.

Final Thoughts

I won’t say that Multiplicative Modifiers are superior to Additive Modifiers in all cases, but they may produce better results for abilities that have large enhancement modifiers. -80% in limitations is often crippling even with large enhancements. The main drawback is that using Multiplicative Modifiers requires recomputing cost of most pre published abilities and may even necessitate redesigning abilities. The -80% cap encourages Limited Enhancements (B111) which makes for more complex builds but may also allow for additional interesting options.

I may do something similar for Sorcery and Divine Favor at some point. I totally haven’t done the work already.