In RoE, pets come in two flavors. Organic pets are what you would expect, furry animals (or sometimes slimy, scaley, or hairless even) that accompany you, and can fight for you. The other type of pets are mechanical pets. These are drones, and probes, and other kinds of helper robots that will do things for you.
Pets have varying levels of loyalty, and they get more powerful the higher their loyalty is to you. You can increase loyalty (or access level for mechanical pets) by feeding them (or performing maintenance). At the lowest loyalty, your pet will have 10hp, and do 1d6 damage. At the second highest loyalty level, your pet has 20hp, and will do 1d10 damage. When your pet is fully loyal, it will gain 50hp, and will deal a total of 1d20 damage. Organic pets deal melee damage, and mechanical pets deal ballistic damage.
All pets have a single magika slot. Their owner must hold a magika stone on them (and therefore it is lootable) for the pet to be able to use it. On a pet's turn, it can use the magika stone, and target anyone you direct it to. Magika stones on the pet do not count against or gain benefit from, the three magika stones its owner equips. A pet cannot gain set bonuses from their magika stones either. Pets cannot equip items unless the item is specifically noted to have an effect on the pet however, aisde from the magika stone.
Pets do not die when they are lowered to 0 health. Like players, pets become injured for 4 hours when they are defeated. You can use the Injure feature on your pet to keep track of this wound time. You may also use healing items of the appropriate type by using the Heal option on a wounded pet. Wounded pets will not gain hunger while wounded.
Your pet will get hungry, or need maintenance, once every 3 hours. You cannot feed your pet more often than it is hungry. Every time you feed your pet, it will go up in loyalty. Fail to feed it for an hour, and it's loyalty will go down a point, until it is fed. A pet that reaches 0 loyalty and is still hungry, will run away if not fed for an hour and become unusable.
All of the pet's functions can be accessed by clicking on it, and selecting the appropriate option from the dialog box. When you first get a pet, you will want to set its name, and set its talk channel. When you set the talk channel, you can speak through the guise of your pet by typing your message on that channel. (example: /11 Ruff!) You can also set a pet's wounds (health is automatically generated by the loyalty level), and roll for your pet using the dialog options. Lastly, the Advanced button is used for interfacing with other scripts in the pet, but won't be a valid option unless it is built into your pet.
When it comes time to update a pet, the script will become inactive, and a new pet script will have to be obtained from a staff member. You will not need to do anything to update your pet, aside from removing the original script, and placing the new one inside. All of the original settings will still be saved.