Since there is confusion on what actionscript byte code and actionscript, let me explain.
Flash games are primarily coded in actionscript, this is the language Flash uses for its programs and is what pretty much every flash developer codes in when developing on the platform. Anyone who values their sanity will opt to code in actionscript over actionscript byte code given the choice. It is an interpreted language that is similar to java. Programs made with a interpreted language need an interpreter to run which is why people are forced to download flash (if it isn't already included with their browser) or use the flash projector. Similarly java need the java runtime environment and c# needs .net. These interpreters don't interpret pure actionscript, java, or c# code which is why with these languages you need to compile your code into binaries that the interpreter can read. For flash, this happens to be actionscript byte code. So that .swf you hold on your computer is a set of actionscript byte code instructions. RABCDAsm takes the instructions given in the swf and basically puts it into a format that one can actively edit (which is the actionscript byte code). Programs like AS3 Sorcerer takes it a step further and tries its best to reproduce the actionscript code that was written to make the corresponding actionscript byte code.