Magic

Magic is a set a physical phenomena in universe of Price for Freedom. While it has it's unique properties it is still following laws of thermodynamics and plenty of own limitations.While being very hard to control magic is still very common and i present in almost of places of the earth and is present in majority of lifeforms.

Magic while being a whole science about this phenomena, energy circulating is called aether. Aether can vary greatly in stability depending on density and other factors, more unstable it is more it tries to convert self in different type of energy. Converting it back is very hard, but most highly devleoped live forms produce own ether which can be harvested and stored safely. This process obviously is very energy demanding, so intense ether generation would leave creature exhausted and will increase food requirements greatly, mages and their apprentices are very known for their hearty appetite while often staying relatively lean.

Spells
One of main ways to harness power of magic for civilized world is creating spells, constructs made out out inert Ether which fueled by regular Ether will produce deisred effect. No spell is eternal, as inert Ether will slowly be either degraded or become active again thus eroding structure of spell.

Spell structure is very complex and needs deep knowledge of the mage to be able form energy into proper shape. While spell is virtually invisible, it is still present in material world as untouchable circuit, usually bound to a solid object though it could be in theory bound to air what would make it floating but severely decreases spell reliability.

Spell could be generally divided in 2 parts: aether storage and circuit. Aether storage is self explanatory, it could be within spell but then its very limited and such spell usually are very weak to have practical use, normally material storage like crystals and other are used. To economize many spells are multi-use and can be recharged by replacing storage. Circuit is what when fed by aether will transform it to have desired effect in the end, it is very sophisticated and detailed part which mages spend years learning to make, and hours if not days to actually build circuit. Due such difficulty and need for energy source creating spells rapidly in action is unfeasible idea.

It is worth noting spells can be damaged by magical or physical means. Damaging object to which spell is bound can compromise spell integrity which could lead to unexpected results due aether being unstable.

Practical uses of magic
Spell'lock firearms - a direct improvement from match lock guns. Due simplicity and low energy requirement a very popular solution for military, even though still more expensive than matchlock.

Line breaker armor - a very popular choice for wealthy knights or mercenaries, after gunfire invention made plate armor less effective a solution arrived. Now all those years of training will not be ruined by a peasant with a loud boomstick.

Magic strongboxes\lock - an expensive but a good solution to high security risks. Ways such enchantments work vary greatly from enforcing lock from picking or simply triggering traps to harm intruder or destroy strongbox content.

Explosives - gunpowder can create impressive explosions, but usually bothersome to transport or you need more force in a smaller package. Overloaded spell with aether will violently release energy all around with much bigger effect, it is much more expensive and has own dangers of course.

High quality material crafting - extra durable and strong material sometimes unobtainable without use of magic.

Alchemy - an already science of its own Alchemy often works together with Magic, some exotic mixtures include usage of spells.

Magic motor - an extremely expensive, but possible way to move vehicles. Mostly utilized as exotic military siege machinery.