DEF / MDEF
In pre-renewal, defense has TWO independent parts. Hard DEF (from gear) cuts damage by a percentage; soft DEF (from VIT) is subtracted flatly afterwards. MDEF works the same way, but its soft part scales with INT. So VIT and INT are not vague "less damage" — they are the concrete numbers below.
Why defense matters
Defense (DEF) is how much your character reduces the physical damage it takes. MDEF does the same thing, but against magic. Imagine an enemy hitting for 1000 — with no defense you lose the full 1000 HP, but with solid defense that might turn into, say, 400. The rest just gets eaten up by your armor and your body. The longer you want to stand in a fight without dropping, the more defense matters.
Two parts: hard and soft
The most important thing to grasp from the very start: in pre-renewal, defense is made of TWO separate parts, and they work completely differently. The first part is hardDEF, which is a percentage. That comes from armor, refine, and buffs. The second part is softDEF, which is flat — it subtracts a fixed number. It comes from your VIT (and for magic, softMDEF also comes from INT).
Order and formula
The order of operations is this: first the hardDEF percentage is taken off the damage, and only THEN the flat softDEF is subtracted from the result. The physical formula: result = floor(damage × (100 − hardDEF) / 100) − softDEF, where softDEF = floor(VIT / 2). For magic: result = floor(damage × (100 − hardMDEF) / 100) − softMDEF, where softMDEF = INT + floor(VIT / 2).
Weak vs big hits
Why does this difference matter so much? Because the percentage part (hardDEF) works equally well against any hit — small or large. But the flat part (softDEF) subtracts the same number from every single hit. So against many weak hits, flat defense is wonderful: if an enemy hits for 60 and your softDEF is 45, you take almost nothing. But against one huge 5000 hit, that same 45 is barely noticeable.
Crit ignores defense
And one more key thing: a critical hit (crit) completely IGNORES both kinds of DEF — hard and soft. So against enemies with high crit, armor will not save you; you need other defenses there (Lucky Dodge, FLEE against non-crit attacks, and so on). Keep this in mind when you build a tank.
damage = floor( damage × (100 − hardDEF) / 100 ) − softDEF- hardDEF
- hard DEF — percentage reduction from armor/refine (cap 100)
- softDEF
- soft DEF — flat subtraction, floor(VIT/2)
softDEF = floor(VIT / 2)- VIT
- character VIT stat
magic = floor( magic × (100 − hardMDEF) / 100 ) − softMDEF- softMDEF
- soft MDEF — INT + floor(VIT/2)
softMDEF = INT + floor(VIT / 2)- INT
- character INT stat
| Incoming physical | raw | 1000 |
| After hard DEF | 1000 × (100 − 55) / 100 | 450 |
| After soft DEF | 450 − 40 (softDEF = ⌊80/2⌋) | 410 |
| Incoming magic | raw | 1000 |
| After MDEF | 900 − 70 (softMDEF = 30 + ⌊80/2⌋) | 830 |
An enemy hits you physically for 300. You have hardDEF 40% (armor + refine) and VIT 90. Let us calculate: 300 × (100 − 40) / 100 = 300 × 0.60 = 180. Then softDEF = floor(90 / 2) = 45. Result: 180 − 45 = 135. So out of 300 damage you only took 135 — less than half.
Imagine hardDEF 50% and VIT 80, so softDEF = floor(80 / 2) = 40. A weak hit of 100: 100 × 0.50 = 50, minus 40 = just 10 damage! Now a strong hit of 1000 with the same stats: 1000 × 0.50 = 500, minus 40 = 460. See the difference? The flat softDEF cut the weak hit by a factor of 10, while against the strong hit it is barely felt. That is exactly why VIT defense is so loved by anyone fighting crowds of small mobs.
A mage casts on you for 800 damage. You have hardMDEF 20% (from gear), INT 50 and VIT 60. First the hard part: 800 × (100 − 20) / 100 = 800 × 0.80 = 640. Now softMDEF = INT + floor(VIT / 2) = 50 + 30 = 80. Result: 640 − 80 = 560. Notice that against magic the flat subtraction comes not only from VIT but from your whole INT — which is why mages and priests usually have decent natural resistance to magic.
- hardDEF and hardMDEF are capped at 100% — defense beyond 100% no longer reduces damage (it would mean full immunity, which the game does not grant by ordinary means).
- Flat softDEF is especially strong against frequent weak hits: it subtracts the same number from every hit, so it can almost cancel out tiny hits.
- Against one big hit, flat softDEF is barely noticeable — there it is the percentage hardDEF that decides things.
- A critical hit (crit) fully ignores both hardDEF and softDEF — defense does not save you from crits.
- softDEF in the game also has a small RANDOM component; what is shown here (floor(VIT / 2)) is the GUARANTEED minimum you always get.
- softMDEF against magic = INT + floor(VIT / 2): this is exactly why INT gives not only SP and magic damage, but also magic defense.
- Thinking DEF is one single number. In reality hard (%) and soft (flat) are two different systems that combine in different ways.
- Pumping only VIT and hoping to survive big hits. Flat defense barely reduces big hits — there you need percentage hardDEF from armor and refine.
- Assuming high armor saves you from crits. Crit pierces both DEF types completely.
- Ignoring MDEF on physical characters. Many dangerous enemies and players hit with magic, and without INT/MDEF you fold instantly.
- Confusing the order: first the hardDEF percentage is multiplied, and ONLY THEN the flat softDEF is subtracted, not the other way around.
Formulas verified against the uAthena engine (pre-renewal, Episode 11.2).