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Mu Online is controlled generally using the mouse, although some keyboard functions are available.

Key	Function
(on empty ground)	Move to that location
(on NPC)	Speak to NPC
(on monster)	Start attacking monster using weapon/fists
(on item)	Move to the item and attempt to take it
(on monster)	Attack the monster using skill/magic from the magic list (some spells and skills may work when mouse is over the ground)
(on another player; After selecting an option from the command menu)	Apply command on that person (Person's name must appear in white)
(on another player's name)	Open chat window with the nickname clicked in the whisper box
Q	Drink Health Potion/Eat Apple (regain health, potions/apples required)
W	Drink Mana Potion (regain mana, Mana Potions required)
E	Drink Antidote (heal poison, Antidotes required)
T	Open quest information window
I/V	Open inventory
P	Open party status window
D	Open command menu
F	Open Friends window
G	Open Guild information window
C	Open Character information window
M	Open warp/move window
Enter	Open chat box
Enter (while chat box opened)	Close chat box/send message or command
Tab (while chat box opened)	Switch between chat box and whisper box
↑  and  ↓  (while whisper box is active)	Swtich between whisper nicknames written (up to 5)
Alt	Show item names
Alt+	Take items from ground/Talk to NPC (bypass monsters and other players)
Alt+(0-9)	Use macro (define macro by "/(0-9) MACRO" in chat window
Ctrl+(0-9) (while mouse over skill in skill list)	Set a number to skill
0-9	Switch to skill defined by Ctrl+(0-9)
Ctrl+	Attack other players
Ctrl+	Attack other players with the active skill/magic in the skill list.
Esc	Open main menu