Lua also provides meta methods for a number of operators, such as addition or subtraction. Often, these meta methods might be performed on two separate tables. The rules for which tables a meta method is executed on are as follows:

• If the left-hand side of the expression has a meta method, but the right-hand side doesn't, the meta method of the left-hand side is used
• If the right-hand side of the expression has a meta method, but the left-hand side doesn't, the meta method of the right-hand side is used
• If both sides of the expression have meta methods, the meta method of the left-hand side is used