Quite often psions use their powers to manipulate the Astral Plane and draw upon the astral haze that exists all around them when manifesting their powers. Occasionally they run across astral phenomena known as mindstorms or surges. Some believe that these phenomena are areas of the Astral Plane that have somehow been damaged or modified by the use of psionic powers.
Mindstorms and surges are similar to maelstroms and sparks found in the Magic of Faerûn (page 42). Additional information on astral haze can be found in the Manual of the Planes (page 47). Neither of these phenomena affect arcane or divine items or casters.
The mindstorm phenomena drain power from psionic items and disrupt manifesting of powers and psionic combat within range of their influence. They can occur in every type of landscape from the deepest of dungeons to the snow-covered peaks of the highest mountains. They are invisible to the eye, but psionic creatures may sense them mentally, as mindstorms feel like a building tempest in those who have the ability to use psionics.
The occurrence of mindstorms appears to be random. Once they begin, they can rage for several days, often fluctuating in size during that time span. They eventually dissipate, leaving behind no trace of their existence. As no one knows how to destroy them at this point, they are virtually indestructible and can influence a sphere of area up to 20 feet in radius, which can spread out to 60 feet in radius every few hours.
Psionic items cease to function in a mindstorm and lose one charge every minute that they are in the area of influence. Psicrystals loose their personality after 15 minutes in the area of influence and are considered destroyed.
Psionic characters and creatures with the ability to manifest psionic powers, engage in psionic combat, or use psionic abilities lose the ability to do so while in the area of influence. They lose one power point every minute while in the area of influence. They are entitled to a Spot check (DC 15) to sense the presence of a mindstorm when they move within 20 feet of its outer boundary.
Detect psionics reveals the presence of a psionic aura on the first round and overwhelming strength on the second round. On the third round, the psion may attempt a Psicraft check (DC 25) to identify the mindstorm's boundaries and effects.
True seeing reveals the mindstorm as a swirling silvery cloud reminiscent of a thunderstorm. Blue lightning arcs back and forth between all living matter in the area of influence.
How to Run a Mindstorm: If you wish to introduce a mindstorm within your game, you can do so by building it and setting aside times when it expands to its fullest radius or rolling randomly to generate the length of time, number of fluctuations, and length of time the fluctuations last. If you wish to randomize it, first roll 1d4 to determine the number of days the storm rages, and then roll 1d6 to determine how many times it expands (and space the fluctuations out as you wish). The other option is to roll 1d12 to determine how many hours pass before it expands to a 60-foot radius. You can also roll 1d4 to determine how many hours it remains that large. Once it contracts, roll another 1d12 to see when the next expansion phase falls. The symptoms of build-up can include a headache or a stuffy feeling in the head, and whether a psionic user feels them is determined by the Spot check mentioned above.
The opposite of a mindstorm, a surge is an astral phenomenon that heightens the effects of psionic powers and abilities manifested therein. A surge augments all psionic powers and abilities triggered or active inside the surge's area of influence. It gives +2 manifester levels to any such effect and decreases the power point cost by one point. Psionic characters and creatures recover one power point every minute while in the area of influence. Psionic items expend the standard amount of charges while in the area of influence. Psicrystals are unaffected.
A surge can be as small as a 5-foot sphere and may fluctuate to a radius of 30 feet. It usually lasts for several hours, though some have lasted as long as a day or as little as an hour.
A surge detects (via detect psionics) as psionics of overwhelming strength. A Psicraft check (DC 20) reveals its effects on the third round of examination with the detect psionics power.
True seeing reveals the surge as a shimmering silvery sphere pulsing with a brilliant white light.
How to Run a Surge: Unlike the mindstorm, the surge does not give any advance warning of its presence. It simply comes into being. You can either set up a specific length of time with fluctuations predetermined by you, or you can roll randomly to generate the length of time, number of fluctuations, and length of fluctuations. First, roll 1d6 and 1d4. Multiply the results together. That should give you a range of 1-24 hours. After that, you can either roll 1d4 to determine number of fluctuations (and assign them within the timeframe as you wish) or roll 1d4 to determine how many hours pass before it first surges. (It's conceivable that it won't fluctuate if the length of time it stays in existence is less than this roll.) A roll of 1d4 will determine how many minutes it lasts, then roll another 1d4 to determine how many more hours pass before it fluctuates again!