|This article is about the current version of DF.|
Two dwarves can get married after having a romantic relationship together. Instantly after marriage, those dwarves usually throw a wedding party if there is an available room, such as a statue garden, or a dining room marked as a meeting hall. A dwarf whose spouse dies may eventually develop another romantic relationship and marry againv0.47.01. Marrying will give both participating parties very strong positive thoughts, while the death of a spouse will in turn give the widower an unhappy thought. Dwarves will cancel their current task when getting married.
In order to be eligible for romantic relationships, dwarves must be friends, adults, not have a too-large age difference (which is currently max(10,min(age_1,age_2)/2), be orientation-compatible, and not be too closely related to their friend. The age restriction only applies in fortress mode, so incoming pregenerated dwarves (i.e. migrants) may have a larger gap between their ages. No marriage between siblings has been observed, but cousins or other distant relatives can marry each other.
Dwarves with similar professions are more likely to get married, presumably because they spend more time together than with dwarves they meet otherwise. For example, two miners are likely to become romantically involved, especially in a fort with sporadic mining, since they will be "off work" at the same time and spend that time together frequently.
To enter into a romantic relationship, dwarves must be allowed to idle together in the same room. They will then socialize and build relationships. If they are compatible in terms of age and marital status, they will eventually become lovers and then marry. If not, they will simply become friends. Dwarves with too little free time will not have time for romance. Occasionally, a couple may stay in the "Lover" stage perpetually without ever being married or breaking off the relationship.
Married dwarves sleep together. Because of this, the couple only requires one bed, and any bedroom claimed by or assigned to one spouse will automatically be assigned to both. This also applies to tables, if they are assigned specifically to a dwarf. Married dwarves also will not let themselves be separated - if you expel one, their spouse (and entire family) will follow them. If you request a married dwarf from your holdings to come to your fortress, the spouse will automatically be requested as well.
Dwarves may divorce and re-marry - for example, if their former spouse dies. However, although they may occasionally have multiple lovers, they will never marry more than one person at the same time. Marriages do end if one of the spouses die, even if they get raised as intelligent undead, in which case their relationship status will be reset to 'Friend'.
In an opposite-sex couple, the wife will become pregnant every year, until she or her husband dies, or until the fortress's child limit (or strict population cap) is reached. There are no visible signs of pregnancy, and the only effective means of contraception (other than the aforementioned limits) is physical isolation. However, that doesn't mean a pregnancy will always result in a baby. Pregnancies may end in miscarriage if the dwarf is starving, dehydrated, sustains an injury, etc., which can lead to tantrums from your now-miserable dwarf and possibly a downward spiral of fun.
Many marriages seem to occur during springtime or early summer.
Dwarves are quite slow to form close relationships; several years of non-stop socialization may only form one or two romantic couples. For overseers who want children (possibly because their civilization is extinct), a more proactive approach is often necessary. A good first step is to determine which dwarves are compatible. They must be adults, not have a too-large age difference (which is currently max(10,min(age_1,age_2)/2), be orientation-compatible, and not be too closely related to each other (cousins can marry). Once you have selected couples, the next step is to cause them to idle next to each other as frequently as possible. This can be achieved by assigning them to special "pre-honeymoon" suites containing two beds (each defining a bedroom), enough fancy furniture to make the rooms high-quality, and impassable furniture (statues) to prevent the owners from avoiding each other. (Designate the rooms *before* adding the statues, since you can't designate a room through them.) Reduce your chosen dwarves' workloads and disable all meeting areas (including sculpture gardens, zoos, etc.) to force them to idle in their shared bedroom as much as possible. Note that locking them into the room may be counterproductive since it limits the number of "encounters". With a proper setup your dwarves should be married in a matter of months.
Dwarves do not necessarily marry people of the opposite sex - see the orientation article for more details.
In prior versions, there was a hard limit of 10 years in maximum age difference as a prerequisite for becoming lovers and eventually marrying. Toady eventually extended it because it led to many immortal creatures (such as elves) never finding a suitable match due to having a too dispersed age distribution.