For the sake of keeping it all in one place and not having to dig up older threads.. this should suffice:
Note: This should be about final...
Physical Attacks:
The best examples of an elemental physical attack are Yang's Claws.
Note: Elemental physical weakness for Fire+Ice equipment combinations have also been "corrected" in FF4A as well to not be weak vs Fire+Ice physical attacks. This is an equipment specific attribute, not an monster attribute.
If the target is weak any of the elements in the attack, the attacker's base attack power is multiplied by 2. It is multiplied by 4 instead if the target (a monsters only attribute) has the Weak+ bit set.
The above rule has total precedence over all physical elemental attacks for the SNES version. Weakness has precedence over absorb/resistance, but not Immunity in the GBA version.
For example if Yang has an IceClaw and FireClaw and attacks a FlameDog, the fact that it is weak vs ice has precedence over the fact it absorbs Fire.
If the target is immune to any of the elements in the attack, the attacker's base attack power is multiplied by 0.
This is most notable with Cecil's Darkness elemental sword vs Zombie monsters (and others).
Note: In the SNES version of the game if you manage to make a critical hit or deal "weird" damage to zombies with Cecil's Darkness elemental swords, the base attack power of the attack is 25.
Immunity has precedence over absorb and resistance, but not weakness in the SNES version. Immunity has total precedence over all physical elemental attacks for the GBA version.
If the target is resistant or absorbs any of the elements in the attack, the attacker's base attack power is multiplied by 1/2.
For example is Yang has a FireClaw and attacks a FlameDog, the base attack power of Yang is multiplied by 1/2 and the FlameDog takes less damage as a result.
Here's a quick reference order of which has priority:
FF4A (GBA)
Immunity > Weakness > Absorb/Resistance
FF2/4 (SNES)
Weakness > Immunity > Absorb/Resistance
Magical Attacks:
Note: In the SNES version of the game, elemental immunity has precedence over elemental absorb. In the GBA version of the game, elemental absorb has precedence over elemental immunity. Absorb/Immunity has precedence over every magic attack.
The best example for this is how the Adamant Armor+Cursed Ring react when both are equipped at the same time in both versions of the game.
Note: An interruptable attack is an attack sequence that doesn't end until the damage or status effects are displayed (which implies the sequence has completed).
Examples of uninterruptable attack sequences include FF4A's ZeromusEG's multi-elemental attack, the ToadLady's Toad attack, and the Dark Elf's multi-elemental attack.
If the target is able to absorb any elementals in the magic attack whether in a solo or uninterruptable attack, all the damage is inverted after being applied against magic defense. If a physical attack is in this sequence, the attack is converted as "healing". This rule has precedence over an entire attack sequence.
If the target is immune to any of the elementals in the magic attack whether in a solo or uninterruptable attack, the base spell power of the attack is multiplied by 0, therefore all damage taken by the target is effectively equal to 1.
If the target is ONLY resistant to any of the elementals in the magic attack whether in a solo or uninterruptable attack, the spell power of the attack is multiplied by 1/2. If this is included in an uninterruptable attack sequence, damage intake will be 1/2 for all the other attacks.
In FF4A, three of the summons in Rydia's Trial are resistant to their notable elementals. They will take far less damage by their favorable elementals.
If the target is ONLY weak to any of the elementals in the magic attack whether in the solo or uninterruptable attack, the spell power of the attack is multiplied by 2. If the target has the "Weak+" attribute (only affects attacks on monsters), the spell power of the magic attack is multiplied by 4 instead. If this is included in an uniterruptable attack sequence, damage intake increase will match whether or not the target has the Weak+ attribute.
Here's a quick reference order of which has priority:
FF4A (GBA)
Absorb > Immunity > Resistance > Weakness
FF2/4 (SNES)
Immunity > Absorb > Resistance > Weakness
Notes:
Darkness Elemental - There is no Darkness magic (the Dave Wave attack is non-elemental for those that are wondering), but it is still absorbable by equipment. You generally notice this in the form of elemental immunity through Zombies and Cecil's Darkness elemental swords.
Aerial Elemental - There is no enemy that has immunity to (or absorb) this elemental, but it still works properly. Also, FF4A's description of this elemental being "resistant" for the Blue Dragon doesn't tell the complete story. This is because there is no Aerial elemental spell. However, a spell given the Aerial Elemental will behave just like Fire/Ice/Lightning elementals does for absorb, immunity, and resistance. Weakness vs Aerial though means immunity to Quake type spells... the equivalent of having the target have Float status.
Drain Elemental - This is a more peculiar elemental. Resistance (1/2 attack power) is applied when the Drain/Absorb bit on the target is enabled (it serves a dual purpose function). If a different offensive spell is given this elemental, the target is directly healed by it (which shouldn't be too much of a surprise) if it has the Drain/Absorb bit is set.
Spells given the Drain elemental don't heal undead targets or hurt you.
Drain+Osmose has no effect, but that's because they are hardcoded, even if you change their elemental properties.
The Drain elemental given to weapons are very consistant at least. Immune+Absorb/Drain bit will make Drain weaponry/attacks deal 1 damage. Drain weakness will allow 2x damage dealt to Drain weaponry. Drain healing is inverted vs Undead...
Weak+/Immune "Elemental" - Believe it or not, this also serves a dual purpose.
Defensively:
Monsters that have this as a weakness increases the power of the spell/weapon by 4x. Monsters that have this as an immunity make other physical and magical attacks reduces the power of the spell/weapon to 0. Armor doesn't have it as a "weakness", which is good.
Offensively:
Weapons that have this as an attribute have their attack power increase by 4x. This is because the Weak+ bit is ALSO the Immune "elemental weakness bit". So let's say we have a weapon that has the Immune bit set. We know that Zombies have the Immune bit. If this "Immune elemental" weapon were to attack the Zombie, the attacker will have his attack power increase by 4x. This has no effect if the monster has this attribute since there is no "Immune elemental weakness" for armor.
FF4A lists doesn't quite list "immunity", but only that a target is resistant (and technically the target is very resistant in this case).
Important note: Elemental multipliers do not stack. If one were to expose the Ice+Aerial weakness of the Arachne monster with the Blizzard Spear or Ice Arrows (which contains both elementals), the character will have his attack power increase only by 4 because of the Weak+ bit. You would be doing the same damage if Fire arrows or the Icebrand is used instead.
We have EVEN MORE themes now, but some old ones are gone...