Guest Post by Anders Starmark
Fairy rings are rings of mushrooms that grow outward, leaving a circle of dark green or dead grass behind them. They can appear wherever the terrain is relatively flat and unobstructed – grasslands are ideal. They are a powerful help for magicians, but can cause bad luck for anyone else.
A fairy ring grows outward at a rate of 9 inches per year, meaning it takes 4 years to grow a yard in diameter. Each yard’s diameter gives it a Circle Strength of 3, so a 3-yard circle has a Circle Strength of 9. Fairy rings rarely grow larger than 10 yards.
In standard GURPS magic a fairy ring is a wild mana area. Any success is a critical success, any failure is a critical failure. If a campaign uses Incantation Magic, Path Magic, or Ritual Path Magic a fairy ring counts as a sacred space, negating the -5 penalty for casting without such a space and giving a net +1 bonus per 6 points in Circle Strength. If a campaign uses Sorcery, magic cast within a fairy ring costs no energy. Fairy rings of dead grass grant their bonuses to necromancy effects only.
Trapping Magical Creatures
Magical creatures (GM’s decision, but elementals, demons and the undead definitely count) find it difficult to exit a fairy ring. To do so, they must overcome the ring’s Circle Strength in a regular Contest vs. the ring’s ST. Each attempt takes 1 minute and if the attempt fails, the creature must wait one hour before it can try again. This makes fairy rings a major boon to summoners, who can summon creatures to question them without risking attack. Note that the creatures have no difficulty entering a ring, so if such a being is ignorant of this property, the ring can be used as a trap. Fairy rings of dead grass can be used to trap undead only.
Destroying the Ring
Destroying a fairy ring is not difficult – no special equipment is necessary (although magical creatures within the ring cannot do so). However, anyone who destroys a Fairy Ring will suffer from the Unluckiness disadvantage for a year and a day. If they already have Unluckiness, increase it to Cursed. If they are already Cursed… then their condition doesn’t get worser. Although such a person probably has enough to worry about anyway.”