How does Advantage Damage work?

[AlexArtsHere]

So playing Heroes and attempting to crunch some numbers has got me thinking; Obviously damage is normally calculated by processing Atk - Def or Mag - Res (disregarding Critical Hits), but how does the Weapon Triangle and Effective Damage (for example, Bows vs Fliers) factor into this? Is a set amount of damage added to the equation, or are one of the equation's stats modified before running the calculation? Heroes may be anomalous for the fact it's a mobile spin off game, but I couldn't figure what exactly is being done in Heroes for, say, Anna to get 2 damage against a Lance Knight, even though her Attack is 16 and the Knight's Defence is 17.

Help me out here, the nerdy side of me needs to know this (there's just something satisfying about crunching numbers manually, y'know?).

[Vaximillian]

Triangle advantage/disadvantage in Heroes is +20%/–20% Attack respectively.

16*1,2≈19, 19–17=2.

Effective damage bonus seems to be +50% Atk.

My Setsuna with 13 Atk shot at a peg knight with 2 Def and did 17 damage to her.

13*1,5≈19, 19–2=17.

Also, wrong forum.

Edited February 3, 2017 by Vaximillian

[AlexArtsHere]

Thanks for the explanation. I'm not sure if this changes whether it's in the wrong forum, but I was also hoping for an explanation of other games, too. Heroes was just the example that got me thinking about it.

[Vaximillian]

As for the other games:

Genealogy: ±20 Hit;
Thracia 776: ±5 Hit;
Binding Blade, Path of Radiance and Radiant Dawn: ±1 Dmg, ±10 Hit;
Blazing Blade and Sacred Stones: ±1 Dmg, ±15 Hit (with reaver weapons doubling the boost or the penalty);
Shadow Dragon onwards: depends on weapon rank, starting at ±5 Hit.

There is also a neat article on the FE Wikia.

Effective damage is usually (weapon Mt)*3, except in Genealogy and Thracia, where it's Atk*2 before enemy Def, Path of Radiance and non-Japanese Blazing Blade, where it's (weapon Mt)*2, and Sacred Stones, where the Sacred Twins have (weapon Mt)*2.

Edited February 3, 2017 by Vaximillian