Game Breaker / Rune Factory 4

• Lest/Frey aside due to them normally due to story mechanics.
• Dual Blades are ridiculously good if you get the Lucky Charm accessory, making each hit do a critical hit which does more damage. The added fact that they also hit more times than the other weapons and that the ultimate art for them results with you doing multiple hits if you are successful means that most bosses aren't going to stand so much of a chance before their already close to defeat.
• The spear shares a similar trait, but only for one of the arts that you learn should you get that weapon skill level to 10. Upon having the skill level for spears hit level 10, your charged attack followed a normal attack in rapid succession results in you doing a flurry of blows so fast that normal enemies can't even move until your assault is over. Combined with the Lucky Charm and the natural long range that spears offer for striking distance means that melee opponents will often die the moment the battle begins. At a high enough level, you can easily kill most non-final bosses like this in under a minute.
• Steel Heart, a Long Sword rune power that you can equip is a mixed blessing and a curse. It lowers your defensive stats... but makes it so your character can't be stunned when attacked, period. This means that whenever you would normally be stunned and be left vulnerable, you instead take more damage but stay standing. This can help you defeat some bosses if you play wisely but can result in a quicker defeat due the fact that you take more damage. Getting it is a bit hard since it's in Sechs Territory and you have to solve a puzzle to obtain it from a chest. Forte also has this ability by default but she rarely uses it in battle.
• Power Wave a Short Sword rune power. It's one of your earliest damage dealing Rune Abilities found in the second dungeon and it's useful for the second boss who melee'ing isn't quite so simple. It does a lot of damage and it travels in a straight line for a while and until it stops, anything in its wake gets hit. Since it also moves through enemies while doing damage, it can easily hit several enemies who are lined up.
• Giga Swing, an Axe/Hammer rune ability. Find yourself being cornered? This ability sends enemies hit flying backwards or away from you until the hit a solid obstacle. Doesn't really work on bosses who are immune to this kind of attack but useful for getting out of rooms where hoards of enemies like to team up against you.
• In general, Cure Spells are a blessing. Master Cure is very costly, requiring a lot of RP (unless you maxed out the uses to where it doesn't require so much RP) but healing both you and your allies HP by a ton. Overall, Cure, Cure All and Master Cure can also revive your fallen allies which is a wonderful trait in hard dungeons but Cure All can heal allies who are far away from you in the same room which Cure can't do while Master Cure can heal everyone in your team who's just about in the same room you are in.
• In the 'Cures' Spell section but for different purposes we have Medipoison, Mediparalysis and Mediseal which only affect the player. Medipoison and Mediparalysis do just as they say, curing you from poison and paralysis respectfully. Mediseal is unique in that a few bosses and normal enemies have attacks that seal off your ability to use rune abilities...Mediseal however isn't affected. What this ability does is remove that ailment so you can use your rune abilities again, very useful and trivial to have once you get into the second arc where enemies start using just about every status ailment on a daily basis and in the final arc where every enemy starts using status ailments.
• Earth Spike, an Earth Elemental rune ability. Yeah, it homes in on one of your enemies and doesn't end until it hits them. Unfortunately, two bosses and certain enemies also have this ability as well. Still it makes it good for hitting annoying flying enemies like Thunder Birds and Hornets who are a nightmare to melee.
• Time for unique abilities that work for your ally monsters. Iron Waltz boosts your ally monsters' defensive stats allowing them to tank hits as they take less damage from enemy attacks for the duration of the day it was used, pretty useful when combined with Cure All or Master Cure since you can use your ally monsters as meat shields when under pressure. Striking March is like Iron Waltz, but instead boosts their offensive stats such as physical and magical attack, good for elemental fairies and minotaurs who are incredibly powerful in their respective offensive stats. Lastly there is Bonus Concerto...the description says that it makes your ally monsters fight with their best efforts. Instead it has you hurl your ally monsters at your enemies and the damage dealt is equal in proportion to their stats. Essentially, it helps you get some of the lazier monsters you have that normally don't attack to move by having you throw them at the enemies nearby you. Since monsters tend to have much higher stats than your human allies, your well raised ally monsters will often do more damage than you can thanks to this ability.
• Thorough exploitation of the Forging and Crafting mechanics, once you grind them past skill level fifty, will allow patient players to take advantage of inheritance mechanics and stat bonuses from upgrading with high-leveled top quality materials, which can result in lower-tier equipment that sport stats and immunities that allow them to compete with endgame hardware (that requires skill levels at 99 to craft).
  • Of particular mention are two special items used for upgading: Two-fold Steel, and Ten-fold steel. Both of them add a multiplied stat boost based on the last item you used to upgrade. With, for example, the Grimoire Scale that grants hundreds of stat points, the ten-fold steel will end up giving you thousands of stat points.
  • To elaborate on the post-level-50 upgrade bonuses, you get bonus stats upon forge upgrades to weapons, armor, and accessories based on the quality level and the "rarity" of the item (Gold crops, boss drops, and generally most items with high crafting difficulty have higher rarity values). If you use 15 level 10 items in crafting and upgrading a weapon, you can get up to +700 attack in total as a forging bonus, and if the total rarity value of the items exceeds 200, you get +2000 attack. These bonuses stack.
  • Using Light Ore as an weapon upgrade material allows you to change the weapon category. This means that you can take heavier weapon like long sword or axe/hammer which have very high attack and slow attack speed and transfer it's stats to faster weapons like short sword or dual blades using Light Ore to create a weapon that has very high attack and fast attack speed.
• Growing pineapples. While they're high maintenance to grow and yield only a decent-to-good profit, what makes them a game breaker is they yield a skill orb (automatically level one random skill per orb) every time you harvest them. And since you net one pineapple per square every day in the summer once fully grown and upgraded, you're able to level all your skills with just one whole field in summer.