How does one overheal exactly..?

[Twilite]

Yeah, sounds like a stupid question, but I'm a long time healer from FFXI, looking to finally go back to the thing I've always been good at and I need to get an understanding of what this truly means, as healing in FFXIV is obviously different..

[PriestAlseid]

Basically overhealing is any time you use a heal that would result in the other person gaining more health than their max, or when you heal someone with a full health bar.

[Anova]

Alseid more or less got it. Coming from FFXI and with a lv.60 blm in ffxiv, you have some understanding about how precious MP is and how enmity works.

Overhealing makes it much harder for tanks to maintain enmity on their target and wastes your MP. It is generally much more preferable for the healer to either stand still and do nothing or use attack spells than to heal 2000 hp every time the tank takes 500 hp worth of damage.

[Twilite]

Alright I was cap happy in FFXI(so to speak). Will have to lower my "healer's threshold". Yep, unlike tanking, I actually know a thing or two about healing thankfully lol.

[Lyrica_Ashtine]

Snip

Right, but also wrong :P

Overhealing doesn't necessarily make it harder for the tank unless you're seriously trying - mindless AoE healing when no one took damage, for example. If anything, it's more like a dps job constantly dealing damage;

When you deal damage instead, every point of damage you deal is equivelant to 2 points of hp restored in terms of enmity. Dealing damage may actually result in more enmity building than single target healing, but shouldn't be an issue if the tank at least knows how to press 123 over and over.

[Pells]

A healer overheals the same way a dps overkills.

Like popping a level 3 limit break to do 50000 damage on a boss with only 50 hp left.

[Lastelli]

Do notice that every healer has in a sense a natural level of overhealing. Generally speaking, a WHM or a Diurnal AST is expected to overheal more than a SCH, for instance, as DoTs usually cause overhealing, whereas shields help reducing it. Ofc there's also the fact that SCH usually DPS, but my point is still valid to some extent. If you have access to a parser, the most important statistics you should look at as a healer is OverHealPct in my opinion. Assuming you're keeping the party alive, the lowest that % is, the better.
Take a look at this, by clicking on the hyperlinks you'll find all the data you need the have an idea of how each healer job should do in that regard.

[Teiren]

I think the reason you're unfamiliar with this is that the pace of battle in FFXI seems roughly 5x slower than FFXIV. I haven't played FFXI past level 10, but I imagine you would actually have to try to overheal because incoming damage in that game seems to be designed to be roughly equal to what can be healed at the same rate. In FFXIV, incoming damage will come in much more rapidly than FFXI, but your healing spells' amount will always be much more than the raw incoming damage overall (by roughly 2x) in normal gameplay. So in other words, HP bars are filled so dramatically fast compared to FFXI that you never need to be constantly healing for normal gameplay.

Honestly, overhealing is not a big deal and no one should ever be getting on your case about it. You really can't run out of MP from just healing unless the tank decided to pull 3 or more groups in a Level 47+ dungeon. MP management is as much of a serious deal as you want to make it, like also casting damage spells in addition to healing spells. The only stupid thing you could do is casting area healing spells when only 1-2 people could use healing.

[Zaj_Quilos]

are people getting sensitive about overhealing now because tanks have trouble with enmity in heavensward?

[Twilite]

I don't know if they are or aren't. I can count how many healers have ripped aggro from me on one hand, as a tank.