In general, Def is best if you take lots of little hits (if "little hits" still aren't hitting the 85% def cap), HP is best if you take a few big hits, and Vit is best if you aren't taking hits.
Def is useless if everything hits for 15% damage already, since boosting it further is meaningless, or if you get hit with Armor Pierce or are afflicted with Armor Broken, since having def at all is pointless.
HP is useless if your current HP is less than your maximum HP, since simply having a high maximum HP means nothing if your current HP never reaches it. ("It" being the maximum hp without using the hp ring, because being over that makes the ring at least partially useful.) Vit is useless if your current HP is equal to your maximum HP, since there's nothing to heal, or if anything can kill you from full HP with one hit, since you'll have no chance to heal afterwards.
A Def ring will reduce damage from a hit instantly. A Vit ring of the same tier will heal the same amount of damage after 5.9 seconds. Therefore, Def is better if you get hit every 5.8 seconds or more frequently, while Vit is better if you get hit every 5.9 seconds or less frequently. Usually, this means Def is better....or is it? (Depends on playing style and class)
This chart compares Def and Vit rings of different tiers. The number is how much time, in seconds, must pass between hits for Vit to be better than Def.
 |
 |
 |
 |
 |
 |
|
|---|---|---|---|---|---|---|
  |
2.0 |
6.3 |
9.85 |
11.8 |
13.75 |
15.6 |
 |
1.2 |
3.55 |
5.9 |
7.1 |
8.25 |
9.45 |
 |
1.0 |
2.95 |
4.95 |
5.9 |
6.9 |
7.85 |
 |
0.85 |
2.55 |
4.25 |
5.05 |
5.9 |
6.75 |
 |
0.75 |
2.25 |
3.7 |
4.45 |
5.15 |
5.9 |
For a Vit ring to heal as much as an HP ring does, you will have to go for some number of seconds for the vit to heal as much as the HP would. This number varies depending on the rings. T1 Vit rings will heal 40HP in 156 seconds, while T5 Vit rings will heal 140HP in 205 seconds. If you can survive that long between taking damage at full health and fully healing, dying, or escaping to Nexus, Vit is better. If you can't for any reason, HP is better.
ERROR: 40hp in 156 seconds doesn't make it better than an 80hp ring in 156 seconds, but in 312.
 |
 |
 |
 |
 |
|
|---|---|---|---|---|---|
|
78 |
156.5 |
196 |
235 |
274.5 |
|
47 |
94 |
117.5 |
141 |
164.5 |
|
39 |
78 |
98 |
117.5 |
137 |
|
33.5 |
67 |
84 |
100.5 |
117.5 |
|
29 |
58.5 |
73.5 |
88 |
102.5 |
If both of these are superior to Vit, you're taking damage frequently. What determines which of the two is better depends on how many of these frequent hits you can take without dying. If you can only survive 17 hits or less, HP is better. If you can survive 18 hits or more, Def is better. (Unless you want to be switching your def and HP rings every time the added bonus from the HP runs out.)
This chart determines how many hits you need to be able to survive for Def rings to be better (Health boost from Ring / Def boost from ring, round up).
|
|
|
|
|
|
|---|---|---|---|---|---|
|
40 |
80 |
100 |
120 |
140 |
|
14 |
27 |
34 |
40 |
47 |
|
8 |
16 |
20 |
24 |
28 |
|
7 |
14 |
17 |
20 |
24 |
|
6 |
12 |
15 |
18 |
20 |
|
5 |
10 |
13 |
15 |
18 |
