Magic on Gero fluctuates. The movements of the stars and planets form an intricate dance, seemingly random, which causes a cyclic effect to occur. While most of the history of Gero has had magic at the "normal level", much of the time is spent in eras of high and low ebbs in magical power. During the low ebbs, many magics simply cease to be. Mystic beasts enter a hibernation-like state, or transform into similar, but more mundane, species. Spells become harder to cast, with many upper-level magics becoming impossible. At the lowest point in the cycle, also called the Nadir, the entire planet is covered by an instantaneous effect which causes many permanent magics to fail and items, particularly scrolls and potions, to be destroyed (the effect is equivalent to a Dispel Magic cast by a 25th-level Wizard). Similarly, during the peaks of the cycle, magic becomes more powerful. The creation of magic items and the design of new spells becomes easier, and new species of mythic beasts come into being. The highest point in the cycle, known as the Convection, is awaited by Ritualists around the planet. Grand Ritae using a Convection as part of their material components have been known to destroy or restore vast swathes of the landscape. Other Rituals have dramatically increased chances of success. Cycles range in length from one day to 1000 years. Furthermore, the length of a down slope does not have to match the length of the adjacent up slopes. Predicting a cycle is difficult, but not impossible. The process is time-consuming, requiring at least six hours of astronomical observation a night for a full cycle of Sym's phases, from new moon to new moon. Each night, the observer must make a successful Astrology Proficiency check. If even one of these is unsuccessful, the month is lost (although the character will not know this until the end of the month). After this, the character must spend another lunar cycle casting the same spell, every night. The spellcaster must make a successful Spellcraft Proficiency check each time. Again, a single failure will render the whole process moot. If the current half-cycle is less than six months in length, however, it is much easier to determine the next high or low point. A single Astrology check, coupled with two successive Spellcraft checks (as above), will reveal everything. In either case, success gives the observer the precise moment of the next Convection or Nadir. It is impossible to predict the shape of the next half-cycle until the current one is finished. Wise Mages always check the Cycle immediately following the event, to make sure the situation is not going to reverse itself before the day is out! (The most drastic shift on record was a Convection-Nadir- Convection cycle completed in one day, sunrise to sunrise.) Psionics are not effected by the cycle. USING THE CYCLE The Cycle can be an excellent tool for the Gamemaster, especially the first time it is used. Since the characters will not start out knowing where on the cycle they are, or how sharp the current slope is, it is perfectly possible for them to be caught completely off-guard by the sudden shift in magical power. A low ebb can remedy a Monty-Haul campaign, while a high one can account for new creatures you want to introduce. Even during the middle of a slope, the Cycle can affect a campaign. Wizards who have managed to plot out the current position of the Cycle often spend years preparing for a Grand Ritae. Such an individual could be a party's sponsor, sending them hither and yon to gather the components she needs for that perfect spell ("You want us to find WHAT kind of egg?!?"). Alternately, an evil Wizard could want some minor, but rare, bauble from the party as one of the elements for his transformation to lichdom. Another possibility comes from false readings. Imagine a respected sage who mistakenly announced that a Convection was imminent, or an elaborate scam based around a (false) prediction of a Nadir in six months....