Early Experience:
At the beginning of the game, Go into the grass and wait on the shadow shaped like a person. Since you are weak, stab the people with spears. Note: you will not get any experience but the will drop items (potion and P-bag) on every sixth one defeated. Be patient and soon you will have enough for a sword upgrade or any of the others.
(supplied by: shadowbassist08)
Hint:
Do not defeat the bosses of the palaces. Get the items and move to the next. Towards the end of the game, you will need a ton of experience to upgrade your weapons and life so go back and defeat the bosses, your experience will continue to rise until you can get an upgrade. It helps for when you need 3000+.
(supplied by: shadowbassist08)
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Legend of Zelda II Cheats at CheatingDome.com.