Until now, medals were Pokémon GO's version of Achievements: rewards that have no gameplay benefit that are given out for reaching certain milestones. That all changed with Pokémon GO's October update, and along with a host of little improvements, Niantic hopes to use the new Catch Bonus mechanic to encourage even more Pokémon hunting.
October's Pokémon GO update adds something called a Catch Bonus to the medals that have to do with catching a certain type of Pokémon – bronze medals have a +1 Catch Bonus, silver has +2, and gold has +3. What this means is that, while the exact math isn't explained, Catch Bonuses of a certain type make it easier for you to catch that type of Pokémon. If a Pokémon is two types, the the Catch Bonuses average.
Either way, this gives the act of just naturally catching Pokémon a snowball effect: the more you catch, the easier it is to catch more difficult ones. To see the different requirements for all the different medals, check out our Medal Catch Bonus Guide.
This is great because it encourages players to do exactly what Niantic wants them to do: catch Pokémon. It also helps mitigate the ceiling that players hit when they level high enough and it becomes just hard enough to catch good Pokémon that it becomes annoying. If you need tips for leveling up, read our guide How to Earn XP and Level Up Fast.
The update also lets you be more friendly with friendly Gyms, upping the number of Pokémon you can train at once in one from one to six. The Pokémon you spar with also get lowered strength and CP so that it really is a sparring session and not a full-on battle. For tips on Gym battles, check out our guide How to Claim Gyms and Win Battles.
Some much-requested smaller changes accompany the October update, including having the distance shown on the Egg and Incubator screen update as you're viewing it instead of only after refreshing. Animation times, audio issues, and other fixes round out the update.
Pokémon GO is still going strong. Join the fun now and check out the Pokémon GO Guides and Tips Hub for everything you need to know.