The Representation of Rules The Number of Possible Rules Initial Conditions Rules Depending on a Single Unary Relation Rules Depending on a Single Binary Relation Rules Depending on One Ternary Relation Rules Depending on More Than One Relation: The 22 32 Case Rules with Signature 22 42 Binary Rules with Signatures Beyond 22 42 Rules Depending on Two Ternary Relations: The 23 33 Case Rules Involving More Ternary Relations Rules with Mixed Arity Multiple Transformation Rules Rules Involving Disconnected Pieces Termination The Effect of Initial Conditions Behavior without Growth Random Rules and Overall Classification of Behavior