I'm perfectly bilingual in English and French but haven't extensively played SoM, so my in-game text translations might be off. I more or less winged this, but nonethless, it's the rumor site in its entirety. Enjoy!
Armlet: THE rumor. It was started by SquareSoft themselves. In the French manual, we see a helmet called Armlet with an unknown price or defense level. Its location is, as if by coincidence, "secret..."
Our opinion: Armlet's existence was proven by Square Palace. At the time it was a world exclusive! Our friend DooKie, in fact, discovered it thanks to an Action Replay code, 7ECC250C !
The secret item
Our friend DooKie by chance "found" a secret item by using Action Replay codes. This item is apparently a healing item since its graphical effect is close to that of the candy or nut. You can download a ZSNES savestate here containing this item. It's in Slot 9. Be careful, your ROM has to be named like the .zs9 file for it to work.
Our opinion: Incredible! 12 years after its release, Secret of Mana can still amaze us ! Where does this item come from and what is it used for ? If you know what it is, don't hesitate to contact us!
A secret character?
While testing on hero status values, DooKie and Poppu by chance found an unused sprite in Secret of Mana! It's not unlike that of the emperor in certain respects. To see this sprite, input the following ZSNES code: 7EE180B3. Who is this person? Gender? Why was he omitted from the finished version? Many questions that'll likely never be answered! One of the "ultimate" secrets of the game!
The character's palette. It's complete, so the sprite is completely finished!
Our opinion: Once again we have a mystery to solve: why not use this sprite? Is it an ennemy? An ally? In any case, it's a Square Palace EXCLUSIVE! Don't forget to change your armor once the code is activated for your sprite to change! If you know who this is, don't hesitate to contact us!
The mysterious island
You've almost certainly seen that island, lost somewhere in the ocean. Many claim it's a secret world with ennemies even tougher than those in the Mana Fortress. Some even claim to have been and found the Armlet!
Our opinion: Secret of Mana was originally intended for the Broadcast Satellite expansion to the Super Famicom. However, it had limited success and was only made available in Japan. It allowed playing games by satellite with a monthly subscription, like with today's internet. The most popular games for this expansion were BS-Zelda and F-Zero Premium Edition.
The main selling point of the expansion was that elements could be added to games, such as dungeons for Zelda, or courses for F-Zero, like patches, without the player losing his current game. Very good for its time, extending the longevity of a game.
But the developers preferred adapting Secret of Mana for the Super Famicom, which was considerably more popular. So certain elements in Secret of Mana don't have any real "meaning," like that head in the ocean. Besides, the biggest "loss" concerning this readaptation concerned weapons and armor: we could take those from the decor and equip ourselves with them (like in the empty rooms in the ruins). However, these features were nixed due to the console's limited memory.
This is why that head-shaped island is there. It was probably there that a submerged continent or the Armlet would be found, something lost since the BS Beta version.
What's more, a second head was discovered in the mountaints. These seem to be some sort of homage or running gag from SquareSoft since we find similar faces in the Final Fantasy series.
Solar
Before entering Puritas for the first time, raise all your magic to level 8:99. Then, enter the Mana Forest and the tree should say "The Legendary Hero Arrives!" instead of ".... I've been waiting! Come here, quickly!" followed by a flash and the solar element appearing. It will say that you alone are worthy of using its magic to triumph over evil. This spell is meant to combine the best attack spells of the eight elements into a single spell, Solar.
Our opinion: This rumor is definitely false despite being quite widespread. It goes against the Mana legend, which specifies eight palaces with one guardian each. Solar therefore can't exist. It's also impossible to raise Magic to level 8:99 (the max at that point being 7:00) since the bucket of seeds was dissolved. Since we're old ROM translators, we scoured the dialogue for lines suspect of introducing Solar, but our search was in vain.
However, the Rainbow spell from Seiken Densetsu 3 corresponds well to the above description.
Sword of Mana
All the hardcore players have asked themselves if it were possible to obtain the last sphere of the Sword of Mana. You can obtain it by exploiting a game bug; as crazy as that sounds, it's the only way. With you have the Flammy drum, go to a small island near the Ice Palace. If you stand in the right spot, you'll find Chacha. Save your game with him. Immediately after, press L, R and START simultaneously. This will reset the game. Start a new game, reach Mantides, and when Elliot starts asking for your protection, reset the game with L, R and START again. Continue the game where you saved with Chacha, and you'll be in front of Mantides! Kill him and you'll get his sphere again. The game continues normally from here...
Our opinion: It's completely crazy but it works! Note that this only works on the American and Japanese versions of the game. The bug was fixed for the European version, so the only way to get the sphere is via an Action Replay.
The real Sorcia?
By using the same technique for finding the mysterious character, we found an unusued Sorcia sprite, shown as an old woman. You can see it using ZSNES code 7EE180BA and moving to the side. It wasn't implemented into the final version but is nonetheless there. Why?
Our opinion: It just gets better and better! An alternate version of Sorcia! Another Square Palace exclusive! Everyone to your ZSNES emulators, and don't forget to change your armor once the code is triggered in order to change your sprite!
A debug room?
Hell found by chance this room which looks a Beta Debug Room. To get to it, use ZSNES code: 7E00DC0F. You can talk to different characters and access the Intro by speaking to the King!
Our opinion: Hell really surprised us with this Action Replay cheat! Are there other rooms like this one in the game? Another mystery!
Kill Jojo
It's possible to kill Jojo, a Plusarkos pacifist. This ferryman can take you to the Moon Palace.
Our opinion: It's true! It is, in fact, possible to kill Jojo! To do this, one must fire an attack spell before climbing on board the ferry. Popoie and his magie "mud" does the job quite nicely. Amusingly, you can kill him as often as you like, by leaving and returning. Poor Jojo...
Infinite HP
You must have four of each curative object. Use them all, one at a time, on a character. Once that's done, he'll be invincible.
Our opinion: Some people like making fools of others.
Invincible
Use the voyage cannon 50 times in a row to be invincible.
Our opinion: No comment...
Return to Potos
After being banished, return to Potos with your three living heroes. Walk against the guard while constantly pressing Select.
Our opinion: This works...but only on the American version, another bug eliminated from the European version. Although, our friend Kenshin found a way to do it in the European version! You just have to press SELECT when the man talks to you and you'll back up towards Potos!! In fact, you have to mess around: for example, by charging him and then quickly changing direction, going forwards and backwards in every direction...but it's very hard to do. But Hell2405 proposes another technique: put yourself close to the man, cast a spell with Purim (like Remedy) and press SELECT repeatedly while going in the direction of Potos. If you're lucky, you can pass. It's a risk but it works. There's a third technique, which works on all versions, which aquamario showed us. It consists of passing "through" the man by using your companions' AI. Rather than talk at length about it, here's a video of Hell showcasing this technique (Click HERE to download)
Sleep as Mimi
It's possible to sleep in an inn with an appearance of Mimi
Our opinion: It's true. For this, it's simple: just transform into Mimi using the Mimi belt before talking to the innkeeper.
Perverted SoM developpers?
Yup, our dear friends who programmed Secret of Mana programmed in something rather amusing! Our friend Xeo_Iwakura found it, and we were very surprised since we never noticed it! It involves Perillo in the Grand Palace, and once of his pages. If you want to see this rather "original" game attraction, hit Perillo several times and with luck you'll see this "hot" page.
Our opinion: A rather amusing aspect of SquareSoft's great classic! Must see at least once!
Level 9 Magic
After getting Level 8 Magic, it can happen that it does special spells, such as dragons instead of fireballs, which would in fact be Level 9 Magic.
Our opinion: This rumor is well-known and proven. All hardcore SoM games know this already... The greater your Magic EXP after Level 8, the greater the chance of casting Level 9 magic. 8:99 Magic will, for example, cast special magic 99% of the time.
Infinite Weapon Spheres
It's possible to have infinite Weapon Spheres. For this, you have to go into a dungeon with a chest containing a sphere, opening it, using magic rope, and going to have your weapon forged. Once that's done, return to the dungeon and the sphere will still be there, allowing as many as you like.
Our opinion: It's actually a misinterpretation. When you find a sphere in a chest, it's possible that the chest doesn't disappear if you missed the previous sphere in a way that you can "catch up." For example, if you open a chest containing a Lance Sphere when you missed the previous one, you'll find two spheres!
A Weapon Sphere vendor
Somewhere, there's a Weapon Sphere Vendor...
Our opinion: Forging a weapon has its price, but a sphere is far too rare to be sold! Don't bother looking, you have to fight to earn them!
Shadow Zero!
Sometimes, a Shadow Zero (an enemy from Seiken Densetsu 3) may come out of a chest. In the English version, the message "Shadow Zero" appears, which in French is "Plus d'ombre." This may seem strange given that this enemy isn't in Secret of Mana but is in its sequel two years later...
Our opinion: The consequences of this trapped chest are unknown to this day...