To "top deck" is to defocate into the cistern of a toilet. The cistern is the water-filled tank often found above the toilet seat, near the flushing handle. Once the cistern has been defiled with faeces, the toilet will begin to flush "shitty" water of a brown, slimy appearance. This not only leaves the victim with a very nasty clean-up job, but more importantly it represents an extreme hatred or humiliation for them.
The art of topdecking is something commonly joked about but very infrequently practised. It is a rare and extreme example of domestic terrorism, often done as a form of revenge or simply to cause gross inconvenience to the victim.
"Man, I'd love to top deck Oxford University..."
- Originating in Magic the Gathering
1.1-Both resedents must be on the top story
1.2-Residents are classfied as a top deck crew (one white one brown)
1.3-The deed must be shared roughly at a 50 50 ratio (performance dependant)
If all these criteria are met you have sucessfully top decked someone. ANd if you were on the other end of the stick(s) you have been top decked.
*Top deck came from cadbury chocolate, half milk half white.