Around Stonecrest is a rift in the weave of time and space. This makes Stonecrest a place that is slightly out of time and space of the island of Kiltayre, and perhaps other places.
Traversing the Rift Weave requires intent and power. Stonecrest is therefore the home of various wizards, sorcerors, geomancers, clerics, priests and archmages.
The mechanic for traversing the Rift Weave is a pretty simple Will save. Base DC is 20 to get through to within sight (0-5 miles) of the location (Kiltayre of Stonecrest). Failure means you’re a random distance in a random direction from the target location area and you take subdual damage equal to the failure margin – which is also the distance in miles.
Example: Base DC 20, Will save total is 14. Displaced 6 miles in random direction and take 6 subdual damage.
However, you can alter the time of arrival by 30 minutes forward or back if you pour power into the travel. This raises the DC by 5 per 30 minutes. Each SL of power added to the group’s travel, if they are tied together, adds to the Will save. A guide, or guides, can add power but not go through the rift.
Minimum power required is 1 SL per person. If time alteration is intended the minimum is 3 SL per person. There is no discount or surcharge for large or small creatures.
Example: a party is going through Rift Weave with a guide. The total SL added to the travel is 16. Each party member who is tied together can add 16 to the Will save. The guide stays behind.
If the DC is 50 or higher, then the power requirements double. This restricts time traversed to 3 hours.
Using the Rift Weave to traverse time more than your level in hours per week has some nasty side-effects– like long-term spell-energy drain (lose PP, or SL, available per day), negative levels, ability drain and in rare cases internal anti-magic matrices that prevent the recovery of any magical energy whatsoever (even Supernatural Abilities).
The last effect of traversing the Rift Weave is the energies can dispel existing enchantments. Roll 2d20 as a caster level check against each effect.
It is a potentially dangerous things and it keeps most hostile spellcasters out of Stonecrest; since they rarely want to arrive depleted.
In light of all this the Rift Weave still has secrets. The time-travel component is not widely known and there are entities within, some attracted to negative energy, others attracted to positive energy. In all it is a risky move and each trip is different.