Red Herring
The Fallacy
Attempting to redirect the argument to another issue to which the person doing the redirecting can better respond.
Why it's wrong
While it is similar to the avoiding the issue fallacy, the red herring is a deliberate diversion of attention with the intention of trying to abandon the original argument.
Example
Mike: It is morally wrong to cheat on your spouse, why on earth would you have done that? Ken: But what is morality exactly? Mike: It's a code of conduct shared by cultures. Ken: But who creates this code?...