Lck: Short for "Luck." Luck is an oddball stat.In addition, Speed increases your character's evasion as well. However, and to use an example, if you have 10 Speed and your opponent has 6 or less, you get to attack a second time. Normally, when you attack an enemy unit, you attack once and the enemy counterattacks once, if able. In Awakening, much like most other FE games, having at least four more Speed than your opponent allows you to Double them. Spd: Short for "Speed." Considered by Fire Emblem veterans to be the most important stat.Criticals multiply the total damage you do by three after factoring in the enemy's defense. Skl: Short for "Skill." Skill improves a character's Hit rate and Critical damage rate.Your total magic damage with a tome is equal to Mag + Tome Damage. Mag: "Short for Magic." The more magic you have, the more damage you do with tomes.Your total damage with a weapon is equal to Str + Weapon Damage. Str: Short for "Strength." The more strength you have, the more damage you do with weapons.While Awakening added an optional Casual mode that removes permadeath (characters who die in one mission are again available in the next), if you play Classic Mode, this value will still be ever-important. HP: Short for "Hit Points." If you run out of HP, you die.
Here's a list of each of the stats present in Fire Emblem: Awakening: