As a rule, the Sages forbade moving things on Shabbat that are not fitting for use on Shabbat and that one puts out of his mind (section 10 below). There are several types of muktzeh:
1) Muktzeh maĥmat gufo (inherently muktzeh) – items that are not fitting for any use on Shabbat, such as rocks, trees, sand, animals, and inedible food (as explained below, section 3).
2) Muktzeh maĥmat ĥesron kis (muktzeh because of monetary loss) – valuable objects that one takes care not to handle except for their sole designated use, out of concern that they will be ruined. Since they have no use on Shabbat, one puts them out of his mind (section 4 below).
3) Basis le-davar ha-asur (a base for a forbidden object) – refers to a case where one places a muktzeh item on an object that is not itself muktzeh; since he intends for it to remain there on Shabbat, he puts the “base” out of his mind as well, and it too becomes muktzeh (sections 5-6 below).
4) Kelim she-melakhtam le-isur (implements whose usage is forbidden) – have a special status. Since they are designed to perform forbidden activities, one puts them out of his mind. On the other hand, sometimes they are used for permitted purposes. Therefore, one may not move them for their own sake (e.g., to protect them, le-tzorekh atzmam), but one may move them to use them permissibly (le-tzorekh gufam) or because one needs the space they occupy (le-tzorekh mekomam) (sections 7-9 below).
If a muktzeh item is painfully unpleasant, like a chamber pot (graf shel re’i), the Sages permitted removing it (section 12 below).
The prohibition is to move a muktzeh object manually, but one may touch a muktzeh item without moving it. Therefore, one may spread a cover over a computer, telephone, or other muktzeh items on Shabbat. One may also move muktzeh “from the side” (min ha-tzad). For example, if one needs to pick up an object or food, and in so doing a muktzeh item that is next to the object or food will be moved indirectly, as long as he does not touch the muktzeh item with his hands, it is not prohibited. However, if the muktzeh item needs to be moved for its own protection, one may not move it even min ha-tzad. As long as he is using his hands, even if they have no direct contact with the muktzeh item (for example, if he is using a broom), it is prohibited. However, one may use any other part of the body (be-gufo); for example, one may move an object that is muktzeh using his foot or elbow (section 14 below).
Sometimes it is unclear whether or not a particular item is muktzeh because we lack facts about the situation. For example, if one found fruit under a tree and it is uncertain whether they fell before Shabbat (and are permitted) or on Shabbat (and are muktzeh), we are stringent and consider it muktzeh (Beitza 24b; SA 325:5). In contrast, if there is a halakhic disagreement about whether an item is muktzeh, the law follows the lenient position (Beit Yosef 279:4; SHT 309:24).