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Increasing Psionic Power in Traveller

This article originally appeared in the September/October 2022 issue.

The standard rules for psionics limit a character’s ability to perform psionic tasks by (temporarily) reducing the character’s PSI characteristic (psionic strength) for each psionic action that is taken. With a character being limited to 12 or fewer psionic strength points (15 or fewer if taking psi-enhancing drugs), and imposing a recovery time after using one’s psionic strength, ‘cinematic’ use of psi tends not to be possible in most campaigns.

The Mongoose rules allow for this, somewhat, by suggesting that the referee multiply a character’s PSI by a suggested factor based on how prevalent psionics is expected to be in the campaign. However, given a group that has two characters that both have the same PSI and a specific psionic talent, there’s no reason to prefer one character over the other for performing activities related to that talent. Yet, in fiction, we see characters that ‘specialize’ in specific psionic fields, and that one character may be ‘better’ at a particular psionic activity than another. How can we simulate that?

I propose two possibilities. Both are additions to the existing psionics rules, rather than wholesale replacements of the psionics system (which has always seemed to me to have been grafted on to the core Traveller rules as an afterthought – but that’s a different discussion for a different article). Both will allow for greater use of psionics in play, but the second represents perhaps an order of magnitude difference in the availability of psionic activity over the first (and over the core psionics rules).

Both require some additional bookkeeping on the part of the players. They essentially graft a pseudo-“skill” system onto the basic psionics rules, and the level of “skill” that a character has in each available talent affects the cost of a psionic activity.

The Common Element

Both options are “set up” the same way; it is only in actual play that they differ. Unfortunately, none of the ‘Classic-compatible’ Traveller rules are really complete, and they differ in certain key ways. The following is a ‘house rule mix’ based on the rules given in Classic Traveller Book 3: Worlds and Adventures (referenced as [W&A] henceforth), the MegaTraveller Players’ Manual ([MTPM] henceforth) and Mongoose 1st edition Book 4: Psion ([B4] henceforth).

The standard rules give each psionic talent a ‘level’ which defines the limits of what a character may do with the talent. This concept is retained. These rules, however, also give each psionic talent an ‘adeptness’, which defines how well/how easily the character can do it.


Testing is a determination of whether a character has access to specific classes of psionic ability (“Talents”). It does not actually allow the character to use them. Use the testing procedure from your chosen version of Traveller; note that if you’re using a version that treats testing as part of training (early Classic Traveller does this), you need to separate them out. Testing, and finding out that a character has access to a Talent, always gives the Talent at level 0. Note that having a Talent at level 0 is different from not having the Talent; a character with a Talent at level 0 can eventually learn to use the Talent and perform activities associated with that Talent; a character who does not have the Talent cannot.

When a player rolls successfully for a character to test for a psionic talent, subtract the roll needed (i.e., the documented target number, not the target number minus the calculated DMs) from the actual (modified) roll. This value is the character’s ‘adeptness’ at the talent. Record the talent and level 0, followed by a slash and the adeptness.

Example: [B4] tests for psionic Talents by rolling a PSI check with the specified learning DM for each Talent, plus DM -1 for each previous Talent attempted. Bero has a PSI of 10 (PSI DM +1) and is testing for Talents. Bero’s primary interests are in Awareness, Clairvoyance, and Telepathy, so testing will be in that order, with Teleportation and Telekinesis being included last for completeness. For Awareness, Bero rolls 2D for 6, +1 (PSI DM), +1 (learning DM for Awareness), giving a total of 8, which is what’s needed to have the Talent, with no particular adeptness. Bero records “Awareness 0/0” on the character sheet. The next Talent to be tested for is Clairvoyance; Bero rolls 7, +1 (PSI DM), +3 (Learning DM for Clairvoyance), -1 (for having tested for one Talent before this) for a total of 10. As the needed roll was only 8, subtract that from the 10, giving an adeptness of 2, and Bero records “Clairvoyance 0/2” on the character sheet. After completing testing, Bero’s character sheet shows Awareness 0/0, Clairvoyance 0/2, and Telepathy 0/2; the tests for Teleportation and Telekinesis did not show that Bero had those Talents.


The rules for training in [B4] allow for training in four-month blocks, and result in the character being trained in one talent if successful. I interpret that to mean that the character gains one level in that talent, e.g., going from Telepathy 0 to Telepathy 1. Training applies the Talent’s learning DM and the learning DM based on the quality of the ‘school’ to a basic roll of 8+. A character may not be trained in a Talent that s/he did not successfully test for (that is, a character that did not successfully test for Teleportation may not be trained in Teleportation in the hopes of gaining even Teleportation 0).

When rolling for successful training, record the difference between the required (8+) roll, and the actual roll. This roll, referred to as the understanding, has no effect on the character’s level in the talent – if the roll succeeds, the level goes up by one. It does, however, have an effect on the adeptness for the talent in question. Compare the character’s current adeptness in the talent with the understanding. If the understanding is greater than the adeptness, change the adeptness to the understanding. If the understanding is less than or equal to the adeptness, add one to the adeptness.

Example: Bero, from the example earlier, has Telepathy 0/2, and takes a four-month block of training in Telepathy at a Psionic Institute rated Good. The Institute’s learning DM for being a Good school is +2; the learning DM for Telepathy is +4. Bero can only fail by rolling an unmodified 2 on 2D; the roll turns out a 4. When the two learning DMs are added, the final roll is 10. Since Bero only needed 8+, subtract 8 from the roll of 10, and understanding is 2, equal to Bero’s adeptness, so increase the latter by one. Bero now has Telepathy 1/3. Had Bero rolled a 7 before adding the learning DMs, the total would have been 13, and understanding would have been 5. When compared to Bero’s adeptness, 5 is greater than 2, so Bero’s adeptness would have been set to 5, giving Telepathy 1/5.

Using Adeptness in Play

Option 1

When a character uses a psionic Talent, calculate the cost in Psionic Strength Points (PSP) normally, and if the total exceeds the available Psionic Strength, the activity is disallowed. If the activity is allowed, add the adeptness for the talent to the character’s PSI DM, and divide by two. Subtract the result from the PSP cost. The result may not go below the minimum allowable cost for the activity (and must be at least one PSP.)

Example: Using the rules from [W&A], the activity “Read Surface Thoughts” requires Telepathy 4 and costs 2 PSP plus range. If the character attempts to “Read Surface Thoughts” from someone at Long range, the cost is calculated as 2 PSP (for the activity) +3 PSP (for Long range) for a total cost of 5 PSP. If she has 4 PSP or fewer available, she cannot do this activity. If she has PSI 9 and Telepathy 4/3, her PSI DM is +1 and her adeptness is 3, so we sum the two (for 4) and divide by 2 (for 2), and subtract the result from the cost of 5. The resulting cost for this activity is 3 PSP, but she still must have 5 PSP or more available to be able to attempt the activity.

Had she instead been attempting the activity against a target at Close or Short range, subtracting 2 from the total cost (2 for the activity, plus 0 [for Close range] or 1 [for Short range]) would have brought the cost below 2; since the minimum cost for the activity is 2, the character’s adeptness and PSI DM cannot bring the total below this level, and the cost will be 2 PSP. The requirement for the character to have 2 PSP (for Close) or 3 PSP (for Short) available still applies.

Option 2

As with Option 1, when a character uses a psionic talent, calculate the cost in Psionic Strength Points (PSP) normally, and if the total exceeds the available Psionic Strength, the activity is disallowed. If the activity is allowed, divide the cost by the character’s adeptness in the talent, rounding fractions up. This forces a minimum cost of 1 PSP. Note: An adeptness of 0 or 1 does not have any effect on the cost of the activity.

Example: Under the rules in [W&A], using Telekinesis to move 1kg (e.g., a book) a Short distance requires Telekinesis 5 and will cost 5 PSP (for 1kg) + 1 PSP (for Short range), for a total of 6 PSP. If the character does not have at least 6 PSP available, the activity may not be attempted. If the character has Telekinesis 6/3, the actual cost of the activity will be 6 PSP divided by 3, or 2 PSP. Note that the character must nevertheless have 6 PSP available to attempt this activity.

Improving Level and Adeptness in Play (Optional)

[W&A] allows the character to improve the level of a Talent by rolling a straight 8+ once per month. This is retained in modified form, and is also applied (separately) to improving Adeptness in a Talent. (That is, the character rolls once for improving the Talent level, and a second time for improving Adeptness.)

Instead of [W&A]’s 8+ roll, the required roll for improvement is 10+, with the following optional DMs:

In any session where the character engages in psionic activity, the referee may award one Psionic Improvement Point (PIP) for the Talent most often used in the session. (Any number of characters may earn PIPs, but no character may earn more than one PIP in a single session.) The character should record the PIP and the Talent for which it was awarded, e.g., “PIP Telepathy”. When the character rolls for improvement of a Talent, s/he may trade three PIPs for the Talent for DM +1 on the roll for improving that Talent. If more than three PIPs have been accumulated for a Talent, each three PIPs may, at the player’s discretion, be traded for DM+1. Whether or not the roll succeeds, the PIPs so traded are lost, and the character must start accumulating them again.

Further Optional Rules

If the referee wishes, s/he may apply the Adeptness score to each activity instead of to the Talent as a whole. The initial adeptness score for each activity should be the Talent’s Adeptness score from testing, plus 1D5-3 (for 1D5, roll 1D ignoring and rerolling results of 6), and should be recorded the same way as the Talent (e.g., “Life Detection 2/3”). If Adeptness is applied separately to individual activities, use the Adeptness for that specific activity rather than for the Talent as a whole when calculating the modified cost.

If the referee chooses to award PIPs for improvement, they may be awarded for the Talent as a whole (as above), they may be limited to specific activities rather than to the Talent as a whole, or both, but any one character may earn no more than one PIP per session regardless.

If Adeptness is being tracked separately for each activity, the character may choose to roll to improve Adeptness for an individual activity, but rolling to improve levels is limited to the Talent as a whole. The character may combine activity PIPs to improve a level in a Talent, but all activity PIPs must be for activities that are covered by the Talent. Activity PIPs may not be combined to improve Adeptness for the Talent as a whole.

If the character successfully rolls for improving Adeptness for an entire Talent, the Adeptness recorded for the Talent is raised by one, and the Adeptness for any activity where it is less than or equal to the old Talent adeptness (before improvement) is also increased by one.