Get secret characters
Beat the game once and play Ex.Map in Extra Mode. They will join in the next battle.
Hayden (JP: Heiden) (Class:Forest Knight) - Finish the Ruins, round 5.
Glen (JP: Guren) (Class:Dragon Master) - Finish the Ruins, round 5.
Selena (JP: Serena) (Class:Mage Knight) - Finish the Tower three times.
Ismaire (JP: Ismea) (Class:Sword Master) - Finish the Tower.
Riev (JP: Alvan) (Class:Bishop) - Finish the Tower, 7F.
Orson (JP: Olsen) (Class:Paladin) - Finish the Tower, 6F.
Caellach (JP: Keselda) (Class:Hero) - Finish the Tower, 3F.
Valter (JP: Walter) (Class:Wyvern Knight) - Finish the Ruins, round 7.
Fado (Class:General) - Finish the Ruins.
Lyon (JP: Leon) (Class:Necromancer) - Finish the Ruins three times.
Secret characters
This is how you unlock the secret characters on Eirika's route.
Ross - Have Eirika talk to him. Chpt. 2.
Garcia - Let Ross talk to him. Chpt. 2.
Colm - Have Neimi talk to him on turn 2. Chpt. 3.
Lute - Visit lower left house. Chpt. 4.
Joshua - Let Natasha talk to him. Chpt. 5.
Amelia - Turn 5. Let Eirika or Franz talk to her. Chpt. 9
Marisa - Let Gerik talk to her. Chpt. 10.
L'Archel - Let Eirika talk to her. Chpt. 11.
Dozla - Let L'Arachel talk to him. Chpt. 11.
Ewan - Visit the small house on turn 5. Chpt. 12.
Comrag - Let Eirika talk to him. Chpt. 13.
Gerrick - Let Innes talk to him. Chpt. 10.
Tethys - Let Gerik talk to her. Chpt. 10.
Innes - Let Tana or Eirika talk to him. Chpt. 10.
Rennac - Let Eirika or L'Arachel talk to him. Chpt. 14
Secret Shop Pass
In the mission with Ephraim were you are to capture grado keep there is a rogue with a secret pass. You can steal it with a thief or talk to him with your Lord to buy the rogue and his pass for 10.000 gold. Then in the area below the upper left treasure chest in the corner is a secret shop wich you can only use if you have the secret pass.
Get rid of fog during skirmish
When you see a monster on the map, it mean's there is an extra skirmish battle at the location. The skirmish mission will most likely have fog, which hides the enemy units from your vision until one of your unit's range of vision gets close enough. An easy way to get rid of it, is to go into the mission and reset the game. When the options come up again, choose "restart chapter" and head down to the skirmish location again. The fog should be gone and all the enemies in plain sight for your picking.
Map Mode
Beat the Game
Support Conversation Veiwer
Beat the Game
Super Arena Abuse
When entering the arena, just after the guy takes your money, the text will display what kind of opponent you are going to face. If it looks like you are going to be totally obliterated... turn the power off. Note: This only works while he is telling you who you are fighting. If you start the fight you will have to finish it. Using this you can have lvl 20 unpromoted chars by chapter 5.
Pegasus Triangle Attack
For those who remember this from the first Fire Emblem for GBA, it still exists. To perform it, you must have all of the pegasus riders. (Vanessa, Tana, and Syrene) Then, have them surround an enemy unit. (Have one of them on each side) When a unit is surrounded and one of them attacks, they will perform the pegasus triangle attack. Also, it is possible for all three of them to perform it on one unit in the same round, assuming it is still alive.