Martial Oath: The Unseen Backbone of Tevinter's Military
In Tevinter, the strength of the nation rests not only upon the shoulders of the magically gifted but equally upon the unwavering commitment of its non-mage citizens who form the unspoken backbone of the military force. Non-mage children are conscripted anywhere from age 5 to age 16. This mandatory service, spanning a minimum of 15 years starting from the age of sixteen, is a testament to the belief that every citizen, regardless of magical ability, must contribute to the nation's defense. Powerful families can buy their non-mage children's way out of serving, but will be heavily scrutinized.

Unlike their mage counterparts, who are given the choice to enlist for only 2 years, non-mages face an obligation engraved in the very fabric of Tevinter's societal expectations. Their training, harsh and disciplined, forges them into skilled warriors who learn to navigate the intricacies of battle, fortifying the military ranks with disciplined soldiers. The unyielding structure of their service is underscored by the fact that leaving before the completion of their term is a rare privilege, granted only under exceptional circumstances.

For non-mages, the only permissible exit from their mandated military service is a late-blooming magical ability. If a latent magical talent manifests during their years of service, they are permitted to transition to the ranks of the mage military or pursue other paths within the magical community. However, for those who remain untouched by the arcane, the completion of their term becomes an unalterable duty.

In a society where magic is revered, the prevailing belief among mages is that this compulsory military service provides non-mages with a unique opportunity to contribute to the nation's well-being. They argue that by channeling their physical prowess and dedication into the military, non-mages can demonstrate their allegiance to Tevinter, offering service in a manner deemed fitting for their abilities.

Furthermore, a peculiar avenue for early release exists for non-mages who find themselves in the hands of a high house with enough influence to purchase their freedom. This transaction, though seldom observed, serves as a reminder that even the most disciplined non-mages can be granted release through the machinations of political power.

TLDR;;

• Non-mage children can enter military training through academies from age 5 up to age 16.
  
• Non-mages are required to serve for 15 years, minimum. A child's service starts at the age of 16.
  
• Powerful families may purchase non-mages within the military service, ending their military service early for things such as: marriage to a mage, bodyguard duty, etc.
  
• Mages are allowed to decide if they want to serve in the military beyond their 2-year required service. Mages are not allowed to enter the military until age 16.