Switching is the act of changing the resident who is in control of one's body and conscious mind (i.e. changing the resident who is currently Fronting). It can be unconscious or it can be a conscious act (see forced switching, below).
There are many ways in which multiples switch. In classic examples of multiplicity it is not conscious; it is usually an act of will on a resident's part. If the resident's need or desire to take control is greater than the entity who is currently Front, a bid for control may take place and the personalities may swap, or blend first and slowly swap if the parties are compatible in that way. Of course, that's oversimplifying the situation as there are a great many factors that can come into play.
If other residents are aware of the bid to take control, they may act to block the party from switching to Front (Crisses: I call this "sitting on" them -- it's a form of restraint of the interfering entity, usually to prevent violation of our House Rules).
If the person who is Front actively does not want to be Front any longer, for example in a stressful situation they actively do not want to deal with, they may attempt to step aside and allow someone else to Front.
A Front may actively "step down" so that someone else can take Front, which is a more common situation in amicable multiple systems. A resident has politely, if unconsciously, made it known that they'd like a turn at Front, or they'd like to handle a specific situation, and the system and the current Front has given them leave to do so. This type of switch can be entirely unconscious and usually doesn't cause any discomfort.
If circumstances cause the Front to completely panic, they may flee from Front entirely, leaving it empty and any residents who are aware then have to either vie to step in, or the residents need to "shove" someone into Front. This can happen quite suddenly and entirely subconsciously, causing a very rapid switch of Fronts and may include disorientation of the new Front, who has suddenly found themselves in control of the body. If a Front flees and no one immediately takes their place, a multiple system probably loses time and to an outsider may seem to be daydreaming, spaced out, etc. (Crisses: In my personal experience this situation doesn't last long, but I've also witnessed that some multiples can curl up in a ball or go vegetative for periods of time until someone regains control of Front.)
Stress or anxiety states may interfere with the switching process, since part of the mechanism of switching involves some degree of unconscious control over one's mental state and what brainwave state you are in. There may be times when a switch is desirable and for some reason a switch is not possible. See also Stuck-front for persons who want to get out of Front or locked out of Front for when a resident would like to get back into Front but cannot. These are both very highly uncomfortable states, and getting further distressed by them does not improve the chances of getting "unstuck".
Forced or active switching is the act of consciously making a switch happen. It's usually best done with everyone's consent and under the lowest stress possible. This switching "on cue" is not usually easy, even with everyone's consent.
"Forced" is a poor term -- it only means that the time, place and whom is switching is actively chosen rather than organically "just happens". One should never attempt to force a switch by brute mental force, willpower, coercion, threats, etc. Switching is usually a matter of the Front simply relaxing into the body and "stepping aside". Switching is more of the simplicity of allowing something to happen than making something happen. The idea is for the Front to surrender to the switch, rather than to try to switch per se. The person who is attempting to Front steps into place rather than jockeying for the position.
Switching by brute force, threats or coercion is both very bad etiquette and can damage your internal system trust levels. However, it may be necessary to remove someone from Front by brute force if they are violating your House Rules. It's not that it can't be done, especially if several residents gang up on the Front to do so -- but you do not want to damage system trust by throwing your weight around without very good reason to do so.
It's also possible to convince a Front to step aside, for example in the case of a young resident who is distressed and would be best advised to return to the internal landscape for further care by more capable residents. One can have House Rules about these types of issues, and it does not have to be a hostile situation if it's in the best interests of the hurting Front. A volunteer resident can take over Front and do external "damage control" of the situation while internal residents care for the hurt resident. This situation is very highly advisable for traumatized systems who are not in professional care or not in the presence of their professional caregiver. It is not always feasible for an adult to behave like a hurt child and expect the people around them to be able to properly handle the situation -- it may be best to handle it internally, and it helps build a collaborative environment and a level of contained responsibility for the system as a whole.
If you have an internal landscape, it gives you a "visual" accompaniment for the interactions that everyone in your head has, which can be very helpful for switching, since you can see and feel your mental movements in a seemingly "real" environment.
Headaches & Switching
Science shows that different Fronts have different brain-chemistry patterns, so switching Fronts causes one's brain to change its chemistry. This may explain why rapid switching or forced switching can cause discomfort and headaches. Switching between more similar personalities, or switching without forcing the switch, may be gentler on the brain chemistry. Meditation (changing to a less stressful brainwave state) and slow switches can help when forcing a shift, as can choosing to blend (co-Front) rather than fully swap residents if that's possible, especially if you expect to be switching back again soon.
- Don't try to force-switch when you feel anxious. If it happens, it happens, but when you're afraid it's harder to get out of the other person's way.
- If you have trouble switching, first work on developing a high level of trust in your system. It's difficult to give someone else the reigns to run "your life" if you can't trust them.
- Corollary: It's easier to switch to people who are "like you" or with whom you have a good relationship with high trust. Work on these types of switches to get used to how it works.
- Work on inner communication with light trance states. It's much easier to have a conversation or a "group huddle" when you're not distracted by what's going on around your body.
- Note that since many multiples are highly hypnotizable (see caution), you need to take care to only go into light or medium trance states. If you enter a very deep trance state, you won't be able to maintain conscious direction during the trance. Try remaining seated, keep your eyes open if possible, or set an alarm.
- Word of caution: If you think that someone hostile might try to take over when you're in a trance state, you still have big hairy trust issues to work on in your system. Go back to the issues of House Rules & how to enforce them, and work on inner communication & trust.
- Try a variety of trance methods. Autowriting, ecstatic dance, progressive relaxation, deep breathing exercises, mindfulness meditations, guided meditation, etc. until you feel comfortable entering trance states at will.
- If you've got entering trance states down, but still don't know how to switch, work on creating an Internal Landscape with your residents. You can use this visual representation of inner interactions to help visualize switching Front.
- If you're going to force-switch, make sure you're in a safe and comfortable environment. Someone might get stuck in Front and you don't want that to become a more stressful situation than it needs to be.
- Before trying full switches, find other ways to blend or give up some of your control of Front before you try a full switch. A resident can write through you, speak through you, "lend" you a skillset such as you doing something they know how to do by tapping into their skills, etc.
- Switching slowly with overlap is less mentally exhausting and has less potential to cause headaches.