Looking for RotMG Packet Guide

[ASERHaerheadrherherh]

There are quite a few C++ guides for making hacks on RotMG already, but does anyone have (or know of) a packet guide?
I'm looking for just a few things:
-Basic guide on what are stored inside RotMG packets
-How to replace packets (simple code please, just to replace a char or few, I know about for loops and stuff already)
-What packet editing is acceptable or not (aka what will get you dced from the server or what does not work)
-Item drop mechanics (Someone told me it works in a swap mechanic, so rip spamming itempickup packets)
-How to add text/stuff into RotMG (aka the text addons that are above your char on K-Relay)
-List of dupes (please pm!) /s

Thank you everyone! My goal for this is to learn how to script and code some hacks and eventually release some for everyone (*cough*not to just download them lol)

[New]

-Basic guide on what are stored inside RotMG packets
-How to replace packets (simple code please, just to replace a char or few, I know about for loops and stuff already)
-What packet editing is acceptable or not (aka what will get you dced from the server or what does not work)
-Item drop mechanics (Someone told me it works in a swap mechanic, so rip spamming itempickup packets)
-How to add text/stuff into RotMG (aka the text addons that are above your char on K-Relay)

-Bytes.
-Replace packets? No idea what you mean. Replace stuff inside packets maybe?
-This is way too generic. Be more specific. You can edit every packet, if done correctly.
-I already told you how it works. Why would you think spamming "itempickup packets" would be something good?
-Notification packet with your own objectID and text of your choosing.

[toddddd]

There are 2 ways you can find out what each packet has in it (the structure). The first, and easier way, is to download the k-relay source and look at all the packet structure files in their. The other way is the do basically the same thing but looking in the client source.

You can also look at the k-relay plugin documentation. It goes over some basic packet info there too.