look
This will show you the room you are in.
look OBJECT
This will display the long description of an OBJECT, whether it's in your inventory or in the room.
look TARGET
You can also look at another player or an npc by using the name you have them recognized by, or by their race.
look [OBJECT/TARGET] [NUMBER]
To identify several similar objects you may append NUMBER to an object, e.g. <look at my sack 2> will display description of second sack in your inventory, or look elf 3
will show you the third elven character in a room.
look my OBJECT
If you specify keyword “my” you'll look only at objects in your inventory, e.g. look at my sack
will display description of sack in your inventory.
look at OBJECT on ground
If you append suffix “on ground” you'll look only at objects on the ground.
look at OBJECT on TARGET
You can look at OBJECTs on people and NPCs by specifying TARGET that possesses the OBJECT, e.g. <look at sword on attacker> will display description of your attacker's sword.
Looking will notify everyone you're visible for about your action. To avoid this you might want to use glance when observing an NPC or another character.
look sky
There is a special object named sky you can look at and see various effects, depending on where an when you are.