Contemporary art seems chaotic. Works can be made out of materials ranging from sugar to ladders to lard. Parts may be intentionally hidden from the audience, objects allowed to deteriorate, and the audience permitted to add or remove things or even damage the objects on display. Sometimes there is no persistent object at all: the work may involve human activity, or temporary objects that are replaced between exhibitions. Contemporary art takes unpredictable forms and often flouts the expectation that artistic creativity involves skilled fabrication of a persistent object. Some find this proliferation of forms and situations exciting – you never know what you’ll find around the bend. For others it is frustrating. Both kinds of audience members, those who welcome the chaos and those averse to it, may be missing key elements of meaning. This is because contemporary art involves a medium that is not always easy to detect when we encounter the work: rules.With traditional paintings and sculptures, the rules were conventional, built in. The artist fabricated a durable object to be displayed for our enjoyment. Museums strived to conserve these objects in close to their original state. We knew what to expect, what to do, and what not to do: look at the work, admire it, don’t touch it.Contemporary artists have been playing with these conventional rules: replacing them with new, custom rules that apply to specific artworks or groups of works. These rules are carefully articulated to achieve specific effects. Just as a painter makes choices about how to apply paint to achieve particular visual effects, contemporary artists make choices about rules to provide particular experiences – in both cases, there are implications for the work’s meanings. Paul Ramírez Jonas invites us to tack a note on to the cork pedestal of a riderless horse, subverting the typical use of monuments to convey the unitary message of the state. Adrian Piper invites us to register our commitments, bridging the separation between art and the rest of life. Babak Golkar offers pottery to muffle our screams.In a context of so many custom rules opening up new possibilities, the choice to use the conventional rule – don’t touch the work – gains new significance as a consciously selected option rather than a default. Janine Antoni doesn’t allow us to touch the chocolate works she has sculpted through licking and gnawing, because she aims for viewers to empathize with her experience: