Usually one junkie baits the other into violent reaction so that he can claim damages in court by saying "Ya fuckin' bam". However, there is actually no space inbetween each word when a junkie uses it. Infact, the faster you can say "Yafuckinbam" the more powerful junkie you are.
Junkie 2: "Wit, yafuckindafty?"
Junkie 1: "Wit, ya bam?
Junkie 2: "Who you callin' a bam, ya dafty?"
Junkie 1: "Who you callin' a dafty, ya bam?"
Junkie 2: *brandishes knife*
Player A typed "BAM" after flopping a full house and wiping the floor with the opposition. Generally used when one is worthy of self-congratulation.