- This article is about the contraceptive device. For the village in France, see Condom, France.
A condom is a device, usually made of latex, that covers a man's penis during sexual intercourse to avoid pregnancy and/or sexually transmitted diseases (STD) such as gonorrhea, syphilis and AIDS. They are also known as 'prophylactics', as well as a number of colloquial or slang terms, such as 'rubbers'.
Origin of the word condom is commonly associated with Dr. Condom or Quondam, a contemporary of Charles II of England, possibly the king's personal physician, who made condoms for the king (the king is believed to have had at least 14 illegitimate children, so we can presume that the early condoms were not very effective, or that their use was not systematic).
The first efforts at making condoms involved the use of woven fabrics. These were obviously not effective. The earliest effective condoms were made of sheep gut or other animal membrane. These are still available today because of their ability to transmit body warmth and tactile sensation, but they are not as effective in preventing pregnancy and disease as synthetic condoms. Mass production of condoms started in mid-19th century, shortly after the invention of the rubber vulcanization process. Until 1930's, condoms were made from rubber; they were still quite uncomfortable and expensive ( though reusable ) and thus only available to small part of population. When latex condoms finally became available in late 1930's, it was a big step forward in effectiveness and affordability. However, before the middle of the 20th century, many places outlawed the sale of condoms, and many subsequently allowed their sale "only for the prevention of disease." Often their availability in a given place was communicated to potential customers in an indirect way, such as advertisements for "rubber sponges." One of the early condom brands was called "Merry Widows".
Latex condoms are packaged in a rolled-up form, and are designed to be applied to the tip of the penis and then rolled over the erect penis. They have a "right side" and a "wrong side" when rolled up, and the first thing the user must do is to determine which side is which before attempting to apply them. Any touching of the penis to the "wrong side" of the rolled-up condom before application potentially 'contaminates' the outside with sperm-bearing fluid, and in this case the condom should be discarded and another condom used.
The early latex condoms were pretty much all the same, except that some eventually came to have reservoir tips to contain ejaculated fluid. One relatively early innovation, the "short cap", only covered the head of the penis. These were a dismal failure in reducing disease and pregnancy.
In recent decades, however, manufacturers have produced a variety of sizes, colors, and shapes of condoms, including ones that are flavored and ones that are supposed to have stimulating properties. Such stimulating properties include enlarged tips or pouches to more easily accommodate the glans penis and textured surfaces such as ribbing or studs (small bumps). Many condoms have spermicidal lubricant added, but it is not an effective substitute for separate spermicide use. One method of testing condoms for microscopic holes involves placing the condom being tested over a conducting form with another conducting form on the other side of the condom. If the condom does not prevent an electric current from flowing between the two conducting forms, it fails the test. Stories about holes in condoms are very likely to be apocryphal if proper handling conditions (see below) are followed.
Condoms made from natural materials (such as those labeled "lambskin", made from lamb intestines) are not as effective at preventing disease. A few companies are today also making condoms from polyethylene and polyurethane, which are expected to be as effective as latex but which have not had as much testing. The alternate materials are useful for those who are allergic to latex.
As a method of contraception, condoms have the advantage of having virtually no side-effects, and of offering protection against sexually transmitted diseases. There is a paradox in the use of condoms for contraception: their theoretical effectiveness is relatively high, but their actual effectiveness is relatively low. This is because many people fail to rigorously follow the proper procedures for condom usage. Even touching the female genitalia with the same (unwashed) hand that removed the condom can potentially cause pregnancy. Furthermore, surveys have shown that many users do not know how to correctly put them on, resulting in bursts and slippages.
So, of themselves, condoms are only moderately reliable, but when combined with a spermicide their reliability is comparable to other methods of contraception. But even when you combine condom use with another method of contraceptives (such as spermicide or birth control pills) pregnancy is still possible. People list among their disadvantages that putting them on can interrupt lovemaking. Some people find them to be limiting their pleasure, because they eliminate skin contact and reduce sensory stimulation; however, a woman can partially solve this problem by training her vaginal muscles, specifically the Pubococcygeus.
Most condom failures are due to misuse. This has led some researchers to ask for earlier and more explicit sex education, but such efforts are fought by religious groups campaigning against premarital sex, who feel that explaining the use of condoms and other contraceptives to youngsters encourages such behavior. However, some studies  suggest sexual abstinence-only programs actually increase instances of pregnancy. A 1994 FHI study showed that most condom users rarely experience condom breakage and/or slippage. 
The use of male condoms involves the following:
- Never handle with sharp fingernails.
- Put on erect penis immediately when an erection is achieved, and definitely before any contact with the vagina or anus. If at all possible, before any contact with the partner's body.
- For the male who has intact foreskin, or has undergone foreskin restoration, the condom is best applied with the foreskin retracted. This will maximize mobility and reduce the chance of breakage during intercourse.
- Leave some room at the tip of the condom to hold the semen: most condoms have a reservoir at the tip. Pinch this when applying to avoid an air bubble, which could cause a burst later
- Water-based sexual lubricants may be used with condoms, but oil-based lubricants should never be used since they weaken the latex and may cause it to tear or develop holes. If the vagina of one's female partner is at all dry, lubricant should be used to reduce the abrasion on the condom, and it is virtually essential for anal sex.
- For anal sex, use condoms designed especially for that. They are a bit thicker and less likely to tear.
- Never use condoms after the date given on the package -- they might seem fine but burst later. Even before the date, don't carry condoms where they will be exposed to body heat for extended periods - such as in wallet (which you keep in your pocket) or directly in the pocket. Don't store condoms in a car's glove compartment as that can get quite hot when the car is parked, again weakening the latex.
- The penis should be withdrawn immediately after ejaculation; even if you can maintain the erection a bit after that, leaving it in still means needless risk.
- When withdrawing the penis, secure the condom at the base so that it doesn't slip off.
- Wash hands and penis before further contact with your partner.
- Condoms are for single use only. Never reuse condoms.
- If you feel regular condoms are either too small or too large, consider using special sizes or the female condom.
- Try on a condom when you're alone, in a well lighted place so you see what you're doing, before using condoms during sex for the first time.
Putting on a male condom involves the following:
- Verify the expiration date on the condom wrapper - Condoms have a printed expiration date and batch number. Do not use out of date condoms.
- Exercising caution, open the foil wrapper along one side. Pay attention and take care not to damage the condom with sharp objects.
- Press firmly together the tip of the condom to expel air that may be trapped inside the condom. Air pockets can cause the condom to burst.
- Put the still-rolled-up condom on the tip of the penis. Ensure that it will unroll the right way before putting it on.
- Unroll the condom over the shaft of the penis. Unroll it all the way. It only unrolls one way - figure out which way is up before the condom touches the tip of the penis.
- Make sure it isn't loose or coming off.
All 12-packs of condoms come with these instructions, and may contain additional information; be sure to read these instructions if you have never used a condom before.
Some men who feel a particular size condom is hard to put on because it is too small have reported that they partly unroll the condom, stretch it with both index fingers, insert the penis (asking their partner to expel air from the tip), remove fingers and unroll. This procedure is not recommended as one's fingernails can come in contact with the condom. Consider buying a larger condom, or practising the approved method above.
Prevalence of condoms
Condoms are most accessible to persons living in developed countries. In various cultures, a number of social or economic factors make access to condoms prohibitive. In some cases, cultural beliefs may cause some persons to deliberately shun the use of condoms even when they are available. 
Recently "female condoms" have become available. They are larger than male condoms and have a stiffened ring-shaped opening, and are designed to be inserted into the vagina. The female condom also contains an inner ring which keeps the condom in place inside the vagina - inserting the female condom requires squeezing this ring. Sales of these have been disappointing, however, so they are not as widely available as they were at first. Probable causes for poor sales are the fact that inserting the female condom is a skill that has to be learned which solitary males cannot practice in advance, as well as reported "rustling" sounds during intercourse. This type of condom is made from polyurethane.
The instructions for use of female condoms are of necessity different from those of male condoms, since they are inserted rather than worn, and designed to drape around the penis, rather than to fit tightly over it.