The guild is a neutral party with concern to international conflict, and as such they cannot interfere directly in wars between nations. However, they are established in numerous countries and often find ways to resolve multi-national disagreements to the benefit of the citizenry involved.
Each guild is separated into what is known as a branch, which are regional constructs where members of the guild, called bracers (遊撃士 Yugekishi?), operate from.
Bracers are divided by their rank, which increases from 10 through 1 for Juniors, and G through A for Seniors. There is also an exceedingly rare S ranking, which is only currently held by 4 individuals. Though not the main purpose for doing so, Bracers can increase their ranking by accepting and fulfilling requests asked of the guild.
Requests can range from the mundane, like monster extermination and finding lost items, to the noteworthy, such as stopping criminals and escorting people and goods. These requests can be of nearly any origin, and offer wildly varying rewards for successful completion.
The Bracer's Guild was founded during the Orbal Revolution, where the members there were extremely beneficial to many types of crimes as they were basically the law enforcers then and now. During the Hundred Days War bracers were also extremely beneficial in helping Liberl regain lost territory from Erebonia.
In Trails in the Sky, the whole motivation for the first installment for newcoming rookies, Estelle Bright and Joshua Bright is to do various missions to try and upgrade their rank from Junior to Senior ranking. They would travel around each region and enter admission into each guild. They would solve a major problem in that region like the missing airliner in Bose or saving Professor Russel in Zeiss then get a recommendation from each region's respective guild then leave. This trend would continue until they saved Grancel and Liberl from Colonel Richard's plan to control it. After that mission, they obtained the final recommendation and they were promoted to Senior Bracer ranking. However their accomplishment was short-lived as a bigger disaster soon befell the duo, while disaster will simultaneously turn into motion for the other Kiseki protagonists across the other countries.