The subject is plain, involves no typical theories, doctrines, principles and concepts and on the balance is marked by the abscence of technicalities.
History has very few concrete theories — the full-fedged theories you find in other streams of humanities like Geography, Sociology, Psychology, Anthropology, Public Administration etc. are conspicuously absent in history.
Theories & Thinkers make a subject complex, History without them become a simple subject—easy to prepare.
Current issues are absent in History what one finds in almost all popular optional subjects like Public Administration, Political Science, Sociology, Geography etc. So preparation doesnot require updating — updating consumes a lot of time. Everything is almost fixed in history.
Since History is static in nature and there are certain relevant and major issues and events which constitute the core of history, it is very easy to guess or visualise issues / questions for the forthcoming examination.
Developmental inter-connections and linkages are dominant in the subject. So an integrated approach works well. The result is if one finishes one topic / issue etc., several other topic / issue are automatically covered.
In the new pattern of GS (Year 2013 onwards) History optional subject has been accomodated almost completely. Though five subjects, History, Political Science, Geography, Public Administration & Sociology have their elements in GS papers, yet History optional subject is the only subject whose almost 90% content are now there in GS (Main + Prelim). So logic is that even if one doesnot have History optional, about 90% of History optional subject one has to study. If a little bit of more preparation is done (beyond 90%) it becomes absolutely the preparation of History optional subject.
Marks-wise, In Preliminary Examination there are about 20 questions from history constituting about 40 marks out of 200 marks and in the Main examination in GS, Paper-I History constitutes about 180 marks out of 250.
The standard of the questions in history optional and history section of General Studies is almost the same excepting some typical history optional questions that are not put in history section of General Studies.
Many books needed in history optional and history section of General Studies are the same such as Ancient Indian History by R.S. Sharma, Medieval Indian History by Satish Chandra, Modern Indian History by Bipin Chandra etc.