If you allow your cat to roam outside in the big wild outdoors, I seriously recommend you take kitty to your veternarian from a young age and start getting him vaccinated! And make sure this is done every year no questions! This is necessary if you don't want your kitty to get infected by nasties like Feline Aids (FIV) which is transmitted through blood while fighting. This also protects your kitty among a lot of other different diseases out there like Feline Leukemia
(FLV). It is also highly advisable to get him (or her) neutered. Unspayed males will fight feirsly for a female if she is in heat, which can leave both cats in tatters and spayed males can find themselves in the middle of something they don't understand if an unspayed males get the wrong idea...
Cats fighting outside at night time can be quite of a shock, as sometimes they can sound close to a child shreking or yelling, and it is definately the last thing you want to hear when your trying to sleep at night! My ultimate way of getting rid of cats engaged in a fight is to turn the hose on them, as noises won't startle them hardly as they are concentrating too much on the other cat!
For indoor cats, obviously water all over the carpet is unwanted so I find usually placing a large object between the two which will cut of eye contact with both cats, if they are engaged in a fight, don't get in their way as cat bites can not only hurt, but are more likely to become infected than dog bites. Use a chair and turn upside down and use the back of the chair and gently slide the chair between the cats, this will startle them and stop them from fighting. Give the cats 'time out' by placing one in a closed room for a short period of time.
A good tell-tale sign if a cat is frightened, the hair will stand up all over the body and when the cat threatens or is ready to attack, you will see the hair stand up in a narrow band along the spine and tail to make him look bigger, and this is also a good time to get out that hose or chair!
With the average lifespan of an outdoor only cat if they are feral or unferal, is only about three years! Which is why if you love your kitty and want him to have a healthy live, keep him indoors and he can live a whopping 16 years longer!
Not only will you benefit from keeping your kitty living longer indoors, it will save you expensive veternarian bills for infected scratches, broken teeth, torn ears, and so on by these nasty one-on-ones.