Power of the World

The Power of the World (世界の力(せかいのちから)) is a mysterious energy source that comes from the earth, a pulse that forms all the forces and flows in the world like blood vessels extending out everywhere.

Principles
The power of the world is similar to the concept of mana and telesma. Like mana, which is formed from the life force of human beings, the power of the world requires refinement in order to be used. Normally, not too powerful, using a temple or shrine, a large amount of power can be generated.

It is nigh-undetectable power even to normal magicians and is described as being like air. Although, specially trained magicians and feng shui masters can detect and see the force. Apparently, Touma's Imagine Breaker can destroy the power of the world, but is apparently ineffective as if the power simply returns back to the earth where it is later destroyed naturally, reverting the power back to the world.

Ley Lines
A Ley Line (レイライン) is a current of power that runs through the earth, using number alignments from terrain and monuments, among other geographical interests. Ley lines are alterable by destroying and reforming the terrain that it runs through, or applying the art of feng shui. However, modification of ley lines is a delicate process, as making a mistake can cause disastrous results. As such, modifications of ley lines are often carried out as big national projects and magicians who use earth for their magic are forced to be careful lest they destroy important magical points.

With modifications, ley lines can be used to strengthen the power that flows through a ley line. They can be described as pipelines and the nodes where they meet up for example, the Avignon and the Vatican, act as reservoirs where other pipes are connected. With this, certain affects can be achieved, such as a spell travelling through the ley line from one node to another, which will then spread that spell's effect through all connected ley lines

There are different types of power that pulsate throughout the earth, with some being important to magicians while being useless to others. Furthermore, these powers also flows in different directions. As such, reading ley lines are different for each culture and can be difficult without clues. Moreover, these types of powers are not apparent in the world, but are just categorizations made by humans.

Once again, Touma's Imagine Breaker is ineffective against ley lines, which is contrasted with Touma not being able to destroy human's life forces with it, despite it being where mana is stored for use in magic.

Deep Blood Arc
It is referred to by Index after journeying into the Misawa Cram School after following Stiyl Magnus' mana trail. Here, it is referenced as a way to describe the incredibly unnatural way the Misawa Cram School has been set up by Aureolus Izzard, seemingly making the building seem to cut and interrupt the flow of the power of the world under the building.