Simply put, bounties in One Piece have been used as informal markers to explain the strength of a pirate, their crew, and any territories they hold dominion over. For the most part, they paint a fairly accurate portrait of the stature of a certain individual, and the overall threat they pose to the authority of the World Government. Throughout the story, the bounties of Luffy and other members of the Straw Hat crew have increased at a steady rate, with the most recent jump after Wano representing their current status as a crew on the level of an Emperor of the Sea. Providing an effective foil to this system, recent chapters of One Piece have also introduced another organization, dubbed Cross Guild, headed by the former warlords Sir Crocodile, Dracule Mihawk, and Captian Buggy, who have put forth their own system of bounties, which apply to the World Government's Marines rather than pirates.
Bounties on their own, are generally perceived as an outline of a character's strength, be it through the use of unique or powerful Devil Fruits, advanced forms of Haki, or just sheer physical prowess. However, they also have a much larger meaning beyond the individual themselves, as many powerful pirates also command large crews boasting combatants who are also extremely strong in their own right. In this vein, any comparisons between Marine bounties and pirate bounties will be difficult since all Marines operate under the World Government and do not command crews or territories of their own. One Piece Chapter 1082 revealed the death of Vice-Admiral T-Bone, who is suspected to have been killed by a desperate civilian who sought his bounty. Examining this new system and its underlying logic may shed some light on the ramifications it could have on the global power balance on the seas, and the manner in which it signals the diminishing power and authority of the World Government, and growing public resentment towards them.
What Are Marine Bounties?
Pirates generally revel in the high bounty values assigned to them, interpreting them as indicators of their power and the sway they hold over the seas. Conversely, Marines are now beginning to live in fear with the bounties that have been placed on their heads, as they are now subject to hunted down much like pirates themselves. While pirate bounties are specified as explicit monetary values that can span from a few thousand berries on average to the billions, with little in terms of a formal grading system, the Marine bounties issued by Cross Guild have a more well-defined structure in their escalation. Much like the system followed by the Donquixote Pirates when they issued bounties on the Straw Hats at the time of the Dressrosa Arc, these bounties are represented by symbols instead. At present, the system makes use of stars and crowns, with each star said to be equivalent to 100,000,000 berries.
Marine ranks come with different combinations of each, with the powerful Marine Captain earning rewards of up to five stars, as seen in Koby's bounty poster. This would mean that his bounty would be equivalent to 500,000,000 berries, as per the system explained earlier. Higher ranked officials such as Admirals, Vice, Admirals, or Rear Admirals will likely have even higher bounties, potentially even in the billions, although Cross Guild's ability to pay out such massive sums is questionable. Furthermore, the idea of a mere civilian being able to fight and defeat such high ranking Marines is virtually unimaginable, considering the impressive displays of power such officers have shown in the story so far. Nevertheless, the ramifications of these bounties are far and wide, bringing a brand-new set of concerns that the World Government will now have to contend with in their bid to end piracy.
How Do They Endanger The Navy?
Before the creation of Cross Guild, the Marines had free rein to enact their own vision of justice, and as such, faced no opposition from any other group other than pirates themselves, or dissenting factions such as the Revolutionary Army. Now, with the introduction of monetary compensation for their capture or elimination, Marines with bounty posters are open to attack from all sides — be it from pirates, those in opposition to the World Government itself, or simply criminals and civilians seeking the rewards for themselves. They can no longer pursue their objectives without any fear of repercussions as there is now a chance that they may also be taken down by agencies beyond their control. This severely weakens the position of the Navy among the Three Great Powers on the seas of One Piece, where there is now a means for practically anyone to place a death sentence upon a Marine or group of Marines.
Furthermore, there is also the problem of treachery and defection among the Marines, as some within their ranks may be enticed to betray their fellow officers, when shown the high rewards on offer. The introduction of Marine bounties will naturally benefit pirates far more than the Navy, apart from the obvious drawback of popularizing the work of extremely powerful Marines by virtue of the immeasurably high rewards on offer for their capture or elimination. Depending on how this system works, it might be possible for disgruntled civilians or pirates, who have been victims of the World Government's corruption and extremism, to use Cross Guild as an avenue to gain revenge, by placing a bounty on the head of those responsible for their plight. Such an option has never been available in the world of One Piece till date, and this would open up the World Government's authority for question, stoking the flames of discontent that are rising across the world.