From The Urban Dead Wiki
Multi abuse is the use of two or more characters in a coordinated fashion.
Important Warning: Multi abuse is commonly referred to by UD players using an umbrella term zerging. For example, the maintainers of the "Zerg Liste" seem surprisingly reluctant to re-title their list with the more accurate: "Ye comprehensive Liste of Zergers, Multi Abusers, Bot Abusers, and other Violators of Kevan's Rules as laide forth in his FAQ." If you attempt to claim that you don't belong on a zerg list because you were caught multi abusing rather than zerging, expect to be subjected to derision and scorn.
- Am I allowed to play multiple characters?
- You are, provided that they lead completely separate existences within the game - your characters should not collaborate, nor share (or stand outside) the same building. Multiple characters found to be working together in a suspicious fashion will be automatically flagged, penalised or even banned permanently by the system. If you're running a few characters, it's best to make sure that they stay in separate suburbs.
The policy explicitly and unequivocally states that your characters should not be in the same building. Operating two or more characters in the same building is de facto evidence of cheating, and could result in penalties (or banning for repeated flagrant violation).
The intention of the policy (emphasized in the original) is that your characters must all lead completely separate existences. Your characters should not heal or revive each other. You should not protect or assist your own alt by barricading, tearing down barricades, or attacking a mutual enemy.
In order to avoid the appearance of cheating, it is recommended that your alts operate in completely different suburbs. Malton is so large that it is easy to maintain three (or five) characters that never come within two suburbs of each other. Please do not put one alt on each side of Caiger Mall and claim that this constitutes "separate suburbs." A good analogy is to fire a flare, if it is seen by another of your characters, your characters are probably too close to each other.
Implemented Anti-Abuse Countermeasures
Currently, anti-abuse countermeasures sometimes cause first-aid kits to fail on your own characters. The countermeasures cause attacks to fail on an enemy that has already been attacked by one of your own characters (since server refresh).
The game designer, Kevan, has stated that these countermeasures are not to be used as a working definition for what constitutes cheating. New countermeasures are implemented without warning. Exact details of countermeasures are purposefully withheld in order to protect the game from abuse by the more obnoxious intentional cheaters.