The Five Precepts are voluntary vows that can be taken. Whether or not you actually vow to keep them, they are the most-basic guidelines for how a Buddhist should lead their life is they wish to get themselves to enlightenment. You cannot become enlightened if you don't follow at least the 5.
There are more than five precepts ... there are actually 10. But for laypeople (those who are not monks or nuns), the first five are sufficient. Except on purification days, when you follow 10 (this too is voluntary for laypeople).
I've included a link, that lists and discusses them, but it is important to understand that there are no "loopholes". "Taking things that are not freely given" includes taking advantage of someone for your own gain (such as non-disclosure of a flaw in your house that might scare off the buyers). Refraining from harming other living beings includes going fishing and it includes swatting mosquitos. Sexual misconduct is harming anyone, sexually/physically/emotionally through your asexual activity, and is usually interpreted as referring to adultery.
Disregard Moe ... they think they are being clever, but they are actually breaking the 4th Precept. This precept says that false speech, even if it's in jest, should be avoided. Yes, Buddhists do laugh and make jokes ... but it falls into the category of "wit" rather than poking fun at others or twisting truth. As a matter of fact, the longer one practices Buddhism, the more we smile and laugh.