Access Control
Access control can be likened to giving a unique passcode to each person who needs to access a door. You are acting on your own behalf.
Within MUD, there are two different forms of access control worth considering: System Access (opens in a new tab) and Namespace Access (opens in a new tab). You should use the prior links to learn more about each. Technically you can add access to anything with a ResourceId (including tables), but these are not recommended.
Namespace Access Control
Namespace Access is a more general and powerful form of access control. It should be used with caution, as someone given access to a namespace can directly write to a table within that namespace. They can also access all the private systems in the namespace, as well as withdraw any ETH in that namespace.
Namespace Owners also have additional rights that should be used with caution. Review the MUD documentation on access control levels (opens in a new tab) for more information.
System Access Control
System Access is a more granular form of access control. It allows you to give access to specific systems that are private and deployed in your namespace. This is useful for giving access to the functions that modify tables under specific conditional logic.