What are cheap tactics for 1 v 1 freestyle?

[King Dain II]

What strategies and tactics are considered cheap for 1 on 1, casual freestyle games? If someone complains that what I am doing is cheap, I stop doing it, but it would be nice to have a list I can refer to and generally know what the community considers to be cheap.

(Not sure if this should go in the Q and A or Strategy sub-forum, so I put it in the general discussion)

[snapdoodle]

In war, and risk, all is fair. Particularly in 1 v 1.

[whitestazn88]

theres nothing cheap about the game of world domination