[Thaum] FWIW: A Variable Mana Weather Generator

[DaltonS]

While I'm not the first to cover this topic, I thought my interpretation deserved a fresh thread. Please add your comments and suggestions.

Mana levels in a given location need not be fixed over time, even in the short term. For instance, a site could have low mana by day and high mana by night, or no mana in winter and normal mana in summer. Fluctuations might be cyclical, variable in other predictable ways, completely random, or something in between – like the weather, chaotic but not totally unpredictable.

GURPS Thaumatology p.58-59

In this scenario, mana levels ordinarily range from very low (p.58) to very high with a few special cases to keep things interesting. No Mana areas created by the Drain Mana spell will remain dead until Restore Mana is applied to them, making them excellent refuges if the weather gets TOO interesting. Naturally aspected areas will retain their aspect, although they may be temporarily altered in very, very special circumstances. I've kept the procedure fairly simple.

When you first enter a new mana zone, set the starting mana level for the area. This can be either by GM fiat, or by rolling a 1d weather die as described below:

1. Very Low Mana.
2. Low Mana.
3. Normal Mana.
4. High Mana.
5. Very High Mana.
6. Special (see below).

If a "Special" is rolled, ignore it and keep rolling until it isn't. Roll 2d to determine how many days until the next "weather roll". When one is due, make a weather roll as above.

• If it is lower than the current mana level, the local mana is reduced by one level for 2d days.
• If the roll equals the current level, it will remain unchanged for an additional 1d days.
• If the roll is higher than the current level (but not "Special"), the local mana is increased by one level for 2d days.
• If a "Special" result is rolled, make another weather roll. If it not "Special", that mana level will persist for 2d days. Otherwise, make another weather roll (ignoring "Special" results) for the new mana level which will last 2d days, then roll 1d for the special circumstance:
  1. Mana Storm!!! Twisted Mana (p.60) for the first 2d hours.
  2-3. Mana is temporarily aspected -1 for the period (GM selects spell college or circumstance).
  4-5. Mana is temporarily aspected +1 for the period (GM selects spell college or circumstance).
  6. Mana Storm!!! Wild Mana (p.59) for the first 2d hours.

Under most circumstances changes in mana level will occur on the average about a week apart, tending towards Normal. If you want a different average mana level add the appropriate modifier to the weather rolls, taking results of 1 or less as Very Low Mana and 6 or more as Special. If you are using a negative modifier and the weather die is 6, roll 1d again; if another 6 occurs, add one level to the previous result. I recommend alternate average levels of Low (-1) or High (+1). If you've chosen Very Low (-2) it will remain there half the time, with "Special" results never occuring. Conversely, with a Very High average level (+2) "Special" results will occur 50% of the time and mana levels will never be less than Normal.

Dalton "looking for his mana umbrella" Spence

[Qhaysh]

Very nice. Simple and very nifty. You could try to expand it into a Pyramid Article.

[ericthered]

I like it!

I think a variant is called for, in places where the manna doesn't vary as much, based on the 3d

5- very low mana
6-8 low mana
9-12 normal mana
13-15 high mana
16+ very high mana

roll a 1d for special cases, on 1 the mana is weird. Use the weird table for that.

This way is a little more stable, and makes the extremes less common. For areas that habitually are higher or lower add bonuses to taste.