The Legend of Zelda: Ocarina of Time/Secrets

Giant enemies
If you repeatedly kill some types of enemy within a short period a giant version will appear. This applies most to the Stalchildren running rampant during the night on Hyrule Field, the Guay located at Lon Lon Ranch and the Leevers at Desert Colossus (in which case actually change colour from green to purple).

Dungeon Map
When you get a dungeon map from a treasure chest, the item that Link holds displays the map for the first floor of Dodongo's Cavern.

Hidden Cave
As Adult Link, after getting the Silver Gauntlets, go to the Zora's Fountain near where you get Farore's Wind. Pick up the gray rock. There should be a hole. Go down it and use the Lens of Truth. Kill the Big Skulltullas and go to the end of the cave. Climb up the wall ladder to be outside of the map's perimeter to the opposite side of the entrance and there should be a treasure chest with fifty Rupees in it. Also, there is an open wall that you can look out of and see a view of Zora's Fountain and Zora River. Here you can jump off into the water. Don't try to use the Hover Boots to get to the little island thing next to Jabu-Jabu's Altar, as you will just land in the water.

Power Stab
If you hold down and press, Link will stab with his sword. However, the power of the stab varies depending on the attack you used immediately before the stab — if you jump-attacked with a Deku Stick then stabbed (without using any other sword attacks), that stab will have the power of the Deku Stick jump attack. This is useful for getting the power of the Deku Stick without wasting your Deku Sticks. This works with any sword attack, Deku Stick attacks, and the Megaton Hammer.

Never lose tunics and shields
When a Like-Like is eating you, equip the Kokiri Tunic and Mirror Shield. Because neither can be purchased, nothing in the environment is able to destroy them, and so the Like-Like can't eat them.

Free money
As Young Link, travel to the drawbridge from the field in front of Hyrule Castle Town. Walk straight up the chain until your face appears to be in the wall then turn towards the middle and jump down. You'll get 20 rupees while you're falling and enter Hyrule Castle Town.
 * Hyrule Castle's drawbridge (20 rupees during the day, and 80 when the gate closes at night)

If you decide to wait until night, climb up and stand on either chain. After the drawbridge raises, walk across the narrow end of the upturned drawbridge to collect 80 rupees (four red ones).

For more free money, go into the hole behind the potion shop in Kakariko Village. Catch a fish in a bottle, and then go back to where the very tall ladder is. Look for the begger who will buy items assigned to C buttons, and sell him the fish. He will give you 100 rupees. You can do this as many times as you want.
 * Kakariko Village (100 rupees)

When entering Hyrule Castle Town from Hyrule, you first see a road with one guard and one openable door. Inside that door is a house full with pots, and a guard that says his job is boring. You can break all the pots you want. After all the pots are broken, go outside, and simply enter again. All the pots are respawned. You can now make infinite money.
 * Hyrule Castle Town (30 rupees per minute)

Kokiri Forest rupee locations for quickly obtaining the Deku Shield
As young Link, when first starting out, this helps you to get the Deku Shield faster. Go into the Kokiri shop, go the empty space to the right, and walk behind it. There you'll get a blue rupee (5).

Jump across the stepping stones that lead to the Deku Tree. As you hop over the last one, it will give you a blue rupee (5). You can do this as many times as you like as long as you enter and exit a house after completing the jumps.

At the training ground, where you go to find the Kokiri sword, you'll see a gate in front of the Know-It-All Brothers' place. Turn left and there will be a sign. Destroy the sign and claim the blue rupee (5) that pops out.

Behind Mido's house (the one where the kid is trying to pick up rocks in front of) there is a blue rupee (5). Also, inside Mido's house there are four chests. Two of them contain blue rupees (5), one contains a green rupee (1), and one contains a recovery heart.

Inside of the area where you can claim the Kokiri Sword there are two blue rupees. The first is located immediately to your right next to a plant after leaving the entrance hole. The next rupee is located in a small nook around the path that the boulder follows. Facing the square path that the boulder follows take a right and then take another right. There should be a blue rupee in this small nook. It should be noted that this is also a good place to avoid the rolling boulder if it should catch up to you.

Lastly, there is a rupee that is located on a platform in the middle of Kokiri village. This is the most annoying rupee to get to but if you must have it then read onward. Find the house that is directly to the right of yours after leaving. There should be a kid who is feebly attempting to pull grass out of the ground. Climb the spiraling wooden walkway to reach the top. There should be three recovery hearts on top of this house. Take the bridge path connected to the roof to get a blue rupee. It should be on a platform with a girl with her hands behind her back.

200 rupees, in Kakariko village, as a kid
This is easier to find if you have the Rumble Pak and Stone of Agony. Enter Kakariko Village, and run up to where the house of Skulltula is, walk up, and walk around the area. Feel the rumble? Bomb the spot where you feel the rumbling. A hole will appear. Fall down the hole. You will now see two ReDeads. Play the Sun's Song to freeze them. Then defeat them by slashing away at them with your sword. After you defeat both of them, a treasure chest will appear. Open the chest, and claim the 200 rupees inside.

200 rupees in Lost Woods as an adult
When you have gotten the Poacher`s saw, in adult Link´s Trading Sequence, you can easily get 200 rupees. In the beginning, go 1 left and stand on the stump. Then quickly go and stab the Skull Kid with your sword. This is easier to do with the Biggoron Sword. When you have killed him he will drop an orange rupee! If you return and go back, the Skull Kid will still be there, allowing you to kill him again. You can kill him as many times as you want, without getting all of the Gold Skulltulas.

Unlimited Rupees
Once you get all 100 Gold Skulltula coins, simply return to the last family member to receive a gold rupee. You can just leave the house and go back in to get another.

Another Unlimited Rupee Trick
In many areas in a hole leading underground you can find a fish, and under many rocks you can find bugs. Swing one of your bottles to capture these fish or bugs, then sell it to the man patting the ground wanting to buy things. He is located in Hyrule Castle Market as a kid, or Kakariko Village as an adult and buys a bug for 50 rupees and a fish for 100 rupees. You can find easy and close fish behind the Kakariko Potion Shop as an adult (by the blue potion lady's house) in the hole.

Gossip Stones
Attacking the Gossip Stones in various manners has a useful purpose outside of entertainment value: by playing Zelda's Lullaby or Song of Storms in front of one, a fairy will emerge. Bombing a Gossip Stone will cause it to flash blue and red and take off after a few seconds. Hitting one with your Megaton Hammer will flatten it temporarily. Even comparatively boring attacks, such as with a sword or a hookshot, cause the stone to vibrate differently, depending on the weapon used.

Chicken Attack
Note: this is a rather dangerous (though quite amusing) pursuit, so do not attempt it if your health is low — one hit from a chicken depletes a half heart container. If you are inclined to be attacked by an enormous horde of chickens, attack one repeatedly until it calls up its buddies, and then run as rapidly as possible in the opposite direction (zig-zag as you run). Two of the better places to do this are at the entrance to Kakariko Village, where there is an easy escape route, or in Lon Lon Ranch, where you can attack them while riding Epona and be invincible to their attacks. Note: Megaton Hammer will work with one attack because it is hitting multiple times with one attack.

Sign Reconstruction
If you ever feel the need to take out your aggression on one of the larger wooden signs with a sword or bomb and subsequently realize that you actually wanted to read it, either leave the room or play Zelda's Lullaby and watch the sign put itself back together.

Crossover Crisis for 20 rupees
There is one crossover in this game: when you first meet Zelda in the castle. If you look in the last window on the right, you can see a picture of a certain famous red-clad plumber and some of his friends. Shoot the picture with the slingshot to get a red rupee. NOTE: For amusement, you can also use the slingshot on the window opposite. A guard will appear and reprimand you before throwing a bomb out of the window.

Stabbing the Cursed Ones
You can actually attack the cursed family in the House of Skulltula just like you do with a regular skulltula. First, wait for one of the family members to drop down, then hit them in the front with your sword. While they're swinging back and forth, quickly run behind them and attack their backside. They will let out a high-pitched scream and be frozen. Eventually they will come to and return the favor, by attacking back, so it's wise to keep your distance.

Stone of Agony
To really find all the secrets around Hyrule, you'll need some help. Luckily, if you acquire 20 Gold Skulltulas you can go to the House of Skulltula in Kakariko village to get the reward, the Stone of Agony, from the person who has been most recently freed from the curse. The Stone of Agony is a rumble pack-shaped passive item that makes your controller vibrate when close to a hole in the ground. When close to one of these holes, you'll have to figure out the special way to open it (bombs, a certain song on the Ocarina, etc.).

If you don't have a rumble pack for the N64 or have the rumble feature turned off, the Stone of Agony will be of no use. Note that the rumble feature is stripped from the Wii version, leaving this quest item useless. However, in Ocarina of Time 3D, the Shard of Agony will flash on the left side of the top screen and make a "bong" sound if there is a hidden item nearby. It flashes more frequently if you get closer to the hidden area. The GameCube version will use the rumble feature exactly like the N64.

A Daytime Dog Companion
If you get a dog to follow you in Hyrule Market at night, you can play the Sun's Song and he'll still be right beside you in the daytime. However, if you run away and the dog goes offscreen, he'll vanish.

Wolfos Treasure Den
At the entrance to the Sacred Forest Meadow, if you have a Rumble Pak and the Stone of Agony, you may feel your controller vibrate. Drop a bomb near that spot, and a hole should open. Inside are two Wolfos. Defeat them, and you'll reveal a chest with a Purple Rupee.

Long Hovering
You can hover a much greater distance with the Hover Boots.Just put on the boots,and then roll out ,walk 2-3 steps and then roll again to hover a lot more out than usual(well,not that much more out,but if succeeded,you`ll be longer out).That comes in handy for a lot of things,like some Heart Pieces.

Skip the Deku Tree
To escape Kokiri Forest without doing the Deku Tree, go to the Lost Woods. As soon as you enter, turn left into the meadow with the dancing flute guy, then go into the only tunnel in that meadow at the far left. Then jump across the logs and you will end up on the bridge where Saria gives you the Ocarina, past Kokiri Forest! Continue on to Hyrule Field. Unfortunately, if you proceed you will not be able to obtain the Master Sword without getting the Forest Spiritual Stone. Therefore, you will be unable to complete the game. However, you can still enter the small towns and do the other parts first and you can come back to Kokiri Forest to complete the Deku Tree dungeon later.