Yes. That is why option writer is always at an advantage provided you manage to sell at the right strike price, else your loses could be huge.
Strategy to short options - http://zerodha.com/varsity/chapter/volatility-applications/
Never be too close to market , in simple words do not choose the strike which is very close to the nifty level, people are even selling sometimes itm call options when market become very bearish but they are really damm good and have great sense of market