GLITCHES

Battlefield Reset
When fighting in a battlefield against an enemy that can selfdestruct, make sure all but that one enemy is dead. Also, make sure your hp is low enough for the selfdestruct to kill you as well. Wait for the enemy to selfdestruct and kill both of you. The battle will end, you will gain all the experience, gp, and even the battle count will decrease, and then it will ask you to try again. Do so and repeat the previous steps until you see that you have won the prize for defeating all the enemies. Win the next battle and exit. The battlefield icon will look like one that has been cleared out and the battlefield will now say: Battlefield Round 255 of 10.


Check SNES chips' version numbers.
In the menu screen, press START and SELECT at the same time. You should then get a box telling you which version number all the chips in your SNES are. Afterwards, the text in the menu screens might act a bit wacky. Just exit the menu and enter it again to fix it. 

Weird little trick for Square to put in the game, eh?


Double Level From Battlefields
Usable with any battlefield that gives Experience points as a reward.

Fight in the battlefield until you have one battle left. Then, go anywhere else, and fight enemies until your experience needed for the next level is within the range that the battlefield gives. (i.e. If the battlefield gives around 200 exp. per battle, get your needed exp. to within 200.)

Then, go back and finish the battlefield. You will gain the level with the exp. gain from the enemies, get the exp. reward, then gain another level.


Life Spell Glitch - US Version Only
On American versions of Final Fantasy: Mystic Quest, there is a particular glitch regarding the Life spell. Like in most Final Fantasies (and the EU/JP versions of this game), it is intended to be able to do extreme damage to undead enemies. However, a few flags got mixed up in the US versions of the game: in this version, you can use Life to kill non-undead enemies, although you can't damage undead enemies at all with this spell.


Partner has incorrect resistances/stats
When you lose a partner and gain a new one, the new partner will retain resistances from your previous partner if you never turned off the game in between. Stats are also affected, but do not remain exactly like the previous partner. The new partner will continue to have the incorrect stats and resistances until you restart the game.


SECRETS
Defeating Doom King Easily
Once the battle with Doom King has begun, cast Cure on him, and you'll do massive damage to the boss. You'll do about 10,000+ to him. That's an easy win against the final boss, dont you think?


Easy Items
Go to any town, and if you find a treasure box, open it. Go out of town, then go back in. Open the box again and the item will be available. This can be of great help when you are stocking 99 of each item.