Roleplayer #25, August 1991

Laying It On The Line

Ley Lines: An Alternate System of Magic

by Tim Keating

Ley lines, also called force lines or mana lines, are invisible power lines that conduct magical energy. In a world where ley lines are common, much of the land is magically barren. Where a mage has access to a line, however, the story is very different!

Using The Lines

Ley lines vary in intensity. Intensity is usually constant along the length of the line, unless the GM determines otherwise. Line intensities correspond to the different levels of mana. When a mage is in contact with a line, he is effectively in a zone of mana equal to the intensity of the line.

What does "in contact with" mean? That depends upon the domain of the lines. The simplest approach is to have two-dimensional lines. In this case, they pass through the ground, or at a set distance above it, along a horizontal plane. Any point above the line is considered to be in contact with it (i.e. if you are standing in or flying above the hex through which it passes, you can access it, so the line has an effective 1-hex width). The energy of the line extends high into the atmosphere, like a curtain. At what altitude the power peters out depends on how much the GM hates airborne characters.

A more adventurous option is to have three-dimensional lines. Three-dimensional lines are not restricted to the horizontal plane, and can pass through the air, up a cliff face or under water. The big disadvantage here, of course, is that such a setup is hard to map out – not only must such lines be mapped horizontally, but their altitude must be determined as well. It also makes it tougher on the players, because being in contact with a line means exactly that. If the line passes 15 feet over your head, then you're not in its 5-yard field, unless you can jump really high.

Mana Radiation

Ley lines radiate mana zones. They run parallel to the line in decreasing order of intensity, with the width of each zone varying according to mana level, as follows:

Low mana15 yards
Normal mana10 yards
High mana5 yards
Very high mana0 yards

For example, standing directly on a very high intensity line, you would be in a very high zone. The next 5 yards would be high mana. 5+ to 15 yards would be normal mana, and 15+ to 30 yards would be low mana.

Standing on a low-intensity line, you would find low-intensity mana for 15 yards in either direction.


Truly the most prized real estate on any magical world must be the places where ley lines come together. At that point, local mana will be increased. Any hex which is influenced by two ley lines has mana equal to that of the higher line, plus one level. The intersection of two normal-mana lines, for example, would produce a high zone in a roughly 10-hex radius around the junction, depending on the angle at which the lines met.

If two lines meet, and one. has very high mana, no "very very high mana" area is produced. Instead, the very-high-mana zone is increased by 1 yard in each direction where it passes through the influence of the other line.

A junction of more than two lines is improbable, unless the GM specifically designs the world that way. This yields some interesting possibilities, though. Imagine that all lines are low-intensity. The junction of two lines yields normal mana, three lines (or four, if you do it exponentially) yields high mana, and four (or eight) gives you very high.

Line Size

All the above discussion has assumed that mana lines themselves are one-dimensional. That is, they have length, but no breadth or height. This need not be so. Depending upon the GM's whim, the world could just as easily have "ley-stripes," "ley-corridors" or "ley-highways." These would increase the width of the line itself, and possibly the radiated mana zones as well. It's up to the GM's taste. However, the wider the lines are, the more the world becomes just another Zoned Mana area.

Detecting Ley Lines

Traditionally, ley lines are invisible. Granted, there may be geographical hints to their presence, and animals will follow them, but only true mages can detect them with certainty. Under the classic interpretation of this system, anyone with Magery can sense the existence of a line. A mage will sense a change when he enters a line's range if he rolls under IQ + Magery. By concentrating for a turn, and making a second roll, the mage can actually see the line itself, as a shimmering light, glowing curtain or whatever.

This is not the sole option, however. If the lines are of divine origin, maybe only priests (or saints) can detect them. Likewise, some races with special senses could have a chance to detect a line as outlined above. Maybe Elves can see them, or Cat-People smell them. They might be completely invisible, requiring the active use of a spell (such as Mage Sight, See Invisible, Seeker or See Secrets, for example), ESP (if it exists in the campaign) or a skill (Dowsing) to find them.

Alternatively, the lines might be visible, appearing as curtains of light or silver threads in the ground. Or they might be marked by strange cloud formations, constructions (like a temple or circle of standing stones) or a series of rune-carved obelisks.

Between The lines

There are two alternatives for the "dead space" between lines. In the first, spaces between ley lines are no-mana zones. This restricts all use of magic to somewhere along a ley line. Under this system, the rules for casting spells into no-mana zones can be ignored, at GM's option (see GURPS Q&A in Roleplayer #20). Unless magic cast from a line is subject to the rules of that level of mana, regardless of the mana level of the subject, spells can only be cast along a line. Of course, leaving this alone would make mages sitting ducks, so it could be a good way to limit magical combat without eliminating combat spells.

In the second option, the world itself has low mana. Spells cast away from the lines are reduced in potency and cost more fatigue. The mage cannot recharge unless he is near a line, limiting him to the "stored mana" that he brings with him, i.e., his natural ST.


According to some myths, ley lines can only be accessed at nodes. Lines can still be detected, as above, but a mage must search along their length to locate a node. The mana zones around a node will be circular if the node is one point, oblong if it extends along the line for a distance. Existing nodes on established lines will be mapped out, and will either be marked or valuable secrets. The former possibility is believed to be the reason for such monuments as the circle of standing stones at Stonehenge.

Mana Storing

Possibly mages can absorb energy from ley lines and store it inside themselves. This is power unrelated to the mage's use of fatigue and hit points. To use this option, exclude the use of Powerstones and allow mage characters to take the Extra Fatigue advantage. Each point of extra fatigue costs 5 points, or 4 points if it may only be used to power magic spells.

One additional way to implement this option is to permit mages to use only the fatigue points from their "pool." This would result in a world where only the experience of the mage determines how much power he has available. A side effect of this may be mages which are physically weaker, as they forgo a few points of ST and HT to buy those all-important spell points.

Mapping Ley Lines

The first thing for the GM to consider when designing a world map for this magic system is the source of the ley lines. There should be a logical reason for where they originate and where they go. Did the gods create them? Are they part of the environment? Perhaps mages created them to monopolize the industry – before the lines were created, the world had regular mana zones. Some device, either magical or technological, absorbs the ambient mana and channels it along the lines. Or maybe there's a generator somewhere . . .

Line Patterns

Ley lines may be either straight or curved. Like intensity, this is usually consistent along the length of an individual line. Both straight and curved lines exist in one of three patterns, as shown below.

Concentric lines are like contour lines on a map. They run parallel to one another in a roughly elliptical shape.

Grid lines run roughly perpendicular to one another, like a city grid.

Haphazard lines run in no particular pattern at all. If they intersect, it is infrequent, making junctions rare and valuable.

There are an infinite number of ways to create a line pattern for a world. A look at any city map will demonstrate that a grid-pattern doesn't have to look like it was drawn on graph-paper. A topographical map can offer some ideas about how to set up concentric lines. Haphazard lines could be random squiggles, look like airport runways, or spell out "Thor is a wimp" in Futhark runes.

Spacing lines

An important consideration when placing lines is line density. If lines are close, there will be little difference from the "zoned mana" system found in the Basic Set. Placing them moderately far apart is recommended. This will yield regular belts of increasingly potent magic, separated by dead zones.

Low density, with widely spaced lines, can also be interesting. Imagine a world where the environment is so hostile that magic is needed to stay alive. Cities would logically be centered around junction points, and would expand narrowly out along the lines. War would be unheard-of, since there would be miles of deadly no-mana between cities – unless they happened to grow into one another on the same line, that is.

Ley lines and Terrain

Ley lines may be affected by geography. For example, concentric lines might surround a central feature, like a mountain. Or they may influence the terrain. Roads will often run along ley lines. The simple explanation of this is that men (or Somebody Else) built the roads along the lines to harness their power. A more subtle possibility is that animals can sense them and follow them instinctively. This creates trails which later become footpaths, and then roads. A road which runs along a ley-line is called a "way," and might be named for the mage who discovered it.

Other Considerations

Aspected lines (p. M84) could exist. This would depend on the source of the energy in the line. A series of concentric lines surrounding a volcano could be fire-aspected, for example.

Campaign Effects

Where this type of magic exists, control over the lines (and especially the junctions) is important unless mages are more rare than ley lines. A city built on a junction has access to far more power than its less fortunate neighbors. Travel tends to follow the paths of the lines, unless they are secret. Staying close to a line offers magical protection and, possibly, aid to speed.

Mages will have to be more diversely skilled than in other fantasy worlds. True, some NPC wizards will be utterly defenseless away from a line, but more adventurous types must expect to spend time in the dead zones.

Finally, as if the Mage's Guild weren't enough, land speculators might get involved! These people would buy, borrow or steal land through which ley lines ran and lease them to mages at exorbitant rates.

Line Potential

Ley lines may provide unlimited power for all users; then again, many mages using a line may reduce the energy available. If the latter is true, set a limit on the number of mages who can use the line without damping it. For each multiple of that number who do use the line simultaneously, reduce the effective intensity by one level. For example, if 100 mages can use a line simultaneously without problems, then 101-200 would reduce it one level; 201-300 would reduce it two levels, and so on.

Depending on the world-designer's whim, this may be a localized effect or it might run the length of the line. In the second case, should the lines be very long, users might experience constant and inexplicable random power fluxes!

Adventure Seeds

Moving Out

A new line has been discovered, miles from civilization. A local mage of some renown wants to go there and set up shop, scooping his peers. There's a problem, however: he has to cross a deadly wilderness without his magic. He hires the PCs as escorts and bodyguards to take him there. His offer is excellent – but will he honor the deal once he's reached the destination and has his powers back?

The Magic Goes Away

The lines have been experiencing strange fluxes lately, with an overall trend of decreasing intensity. The PCs are hired (or decide on their Own) to locate the cause of the problem. This entails figuring out why the lines exist and whether they can be fixed. Meanwhile, PC mages are finding their own magic just as unreliable . . .

Ley Lines in the Real World

The term ley line was coined in the 1920s by Alfred Watkins, a British businessman. Watkins was puzzled by the fact that certain monuments, sites of many religious and magic rituals, seemed to line up almost perfectly. Also remarkable to him was the fact that some roads in Britain (and, it was later discovered, other parts of Europe as well) ran straight for miles in defiance of terrain.

These facts led him to hypothesize the existence of the lines. He described them as channels of force which flowed through the ground. What this "force" was, no one has been able to explain. However, he believed that certain places like Stonehenge and Glastonbury Tor in England marked nodes on the lines where this mysterious energy could be tapped.

Dragon Lines in China

It is interesting to note that the idea of ley lines is not exclusively British, nor even European. Chinese scholars have long been aware of the existence of the lung-mei, or dragon paths. These are supposed to indicate the flight-paths of dragons, and are equated with the lines of energy described by acupuncture which flow through the human body. The dragon lines are believed to convey the force of the nation to the emperor in Peking. And, like the ley lines found in Europe, the lung-mei are dotted with temples and pagodas which show where the dragon-pulse may be most easily accessed.


Parker, Derek and Julia, Atlas of the Supernatural, Prentice Hall Press, 1990.

Asprin, Robert, Myth Adventures and sequels. In this series, magic relies on aspected force lines in some (though not all) dimensions.

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