Despite what some people may say, Fallout
3 is NOT a reskin of Oblivion. It was made by the same company and uses the same engine but Fallout
3 is much different.
It is different in that the gameplay is much different, it is a shooter mixed with an
RPG. The setting is much different; Fallout
3 has a bleak science and political fiction setting while Oblivion has a Roman-era/medieval fantasy setting.
The gameplay of Fallout
3 is also more challenging, the
AI is surprisingly smart and the good guy/bad guy or karma system is far more sophisticated.
And unlike in Oblivion, Fallout uses the V.A.T.S targeting system, which aids you in
gun fights and unarmed and melee
weapon CQCs.