Is a flashgun necessary when taking photos at night or at a party?

I have a Nikon D3000 and a Pentax Super 100 and will be doing a party for some friends and wondered should i use aflash or just turn ISO up and use the flash in the camera suggestions welcome
Sue

It is preferred unless you come up with a crafty solution to overcome severe darkness. Turning ISO up will make the pictures grainy. Use lowest ISO with flash.

The only way to avoid noise is to have plenty of light, a flash does this very well, but only within the range of the flash.

Taking the flash off the camera adds a whole new dimension, but has a learning curve.

Check out the Strobist site for off camera flash using cheap Manual flashguns.

http://strobist.blogspot.com/