1st Law: "When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."
2nd Law: "The only way of discovering the limits of the possible is to venture a little way past them into the impossible."
3rd Law: "Any sufficiently advanced technology is indistinguishable from magic."
Clarke: "As three laws were good enough for Newton, I have modestly decided to stop there."
However, in the The Odissey File; Appendix 2 he states the 69th Law that reads
69th Law: "Reading computer manuals without the hardware is as frustrating as reading sex manuals without the software."