in diablo 2 one of the most misunderstood aspects of the game is how various skills work on gear namely the effects of plus skills, skill charges chance to cast and finally auras when equipped each of these has a set of rules it follows some able to be exploited.
Diablo 2 Resurrected Items Guide- Secret Of Item Skills & Auras
Plus skills
- Always only provide "soft points" to skills
- + All Skills boost non- charge when equipped abilities
- + Class-Specific/ Tree Specific only boost for that class specifically
- " Staff Mods" on providing up to +3 for their original class.
Though some rules do apply at least depending on the type of source, the big rule for all of them is that plus skills are what are known as soft points, they do not contribute to the standard synergy effects, because they only boost the functional level of the skill, such as masteries, druid animal, summons prayer and such do not follow this rule.
Due to how they interact with their linked skills, but for most other skills, it is best to assume these plus skills will not provide a synergy boost as far as the plus skill types themselves, plus all skills functions for any skill, you can use that does not require charges or triggers plus fire skills grants, a bonus to all known fire type skills.
Regardless of class and plus class skills, and plus tree skills, only work for their given class or tree, for example, plus necromancer skills, only boost necromancer skills whereas plus lightning spells, only work for a sorceress, because it's her tree similarly when a single skill lists class only, it will only provide the listed bonus for that specific class, while these class only bonuses are on several different Diablo 2 items throughout the game, they can also spawn naturally as what are known as staff mods, since they were originally generated on staves wands and scepters, but with the lord of destruction were expanded to include new Diablo 2 items, such as orbs necro heads and higher-level assassin claws as well as a druid and barbarian helmets the rules for these spawning, naturally are a bit odd and are determined by Diablo 2 Resurrected item level and while there are exceptions, you will generally find they can only spawn skills of similar levels, for example, you won't find a wand with poison nova and corpse explosion staff mods on it.
Charge
Cranebeak - War Spike
Call Toi Arms - Crystal Sword
Flamebellow - Balrog Blade
Halaberd's Reign - Conqueror Crown
Hellmouth - War Gauntlets
If the Diablo 2 Resurrected item is ethereal, since they won't come back, then now the way these work mechanically is that they cast at the level listed and can not be boosted by plus skills of any sort, but they can be improved by synergies and masteries though due to the limited levels of the skill, this is very rarely something of note and each source of a spell functions, a little like throwing potions or arrows and that quantity left is tracked solely on the source being used and will be used at that level and that level alone as far as where they're found, obviously things like uniques set rune words can get a wide spectrum of the charges, those are at fixed levels and quantities based on the Diablo 2 item, but you can also get them from magic and rare Diablo 2 Resurrected items through suffixes and the higher level the source that dropped them, the higher level, the skill and the more charges, it will have though sadly, most of the skills from charges aside from maybe teleport are generally treated as relatively useless in the end game, but there are a few that can help out with more budget setups, if you know your skills well enough, next up something that functions on a similarly fixed level chance to cast.
Chance to cast
These functions on a few conditions, such as attacks striking being struck levelling up on death and on kills, most of these being fairly straightforward, though there is some wobbliness in the attack and striking options that vary based on the skills being used, so you want to double-check it, especially on the assassin to seeing which ones are carried and under what conditions as far as the skill levels of the chance to cast functions.
They cannot be altered, even stacking identical modifiers by equipping multiple Diablo 2 Items with the same chance to cast will not change the level, it is cast at instead, it will only add the per cent chances together for the sake of the check and obviously going over 100 would be well redundant since it can only trigger, once though it is worth noting to stack, they need to be the exact same skill level and trigger as far as ways to improve the output of chance to cast stuff, while you can not boost their levels, you can boost their synergies and this will impact them, so if you have a chance to cast twister, it can have its damage improved by bumping up a tornado to give it that per cent nudge up it, unfortunately, or fortunately for some Diablo 2 Resurrected items does not work the other way around, since these are not considered hard skills if it worked the other way around you would see some very broken PVP skills.
Auras when equipped
Last but not least is aura when equipped which can only be found on rune words well in Azurath, but that's the only exception currently, and these are an interesting dive into understanding how diablo handles, not only item-supplied Auras but also conflicting and overriding auras and while knowing Hyasura wins as a general rule of thumb is going to serve you best for most of this, the simple stuff starts with aura level, the aura level provided by a Diablo 2 Resurrected item is going to be its listed amount plus any other Diablo 2 item provided or when equipped with the same aura, for example, if you have an edge and a bramble both are level 15 thorns, it works if they're different levels as well, they will both provide level 30 thorns though since thorns are the highest level wins aura, you will only get a single level 30 thorns since it can only win out once. Auras allowing that function to stack, now where all of this gets weird is in the damage auras, as well these follow all the same rules, as the above in that the actual aura will stack and compete and also work with synergies and masteries the wobbly part.
Though damage auras, do not apply their aura to the enemies in the normal sense instead, they just pop off damage at two-second intervals as the aura refreshes, and this means that damage isn't competing. This only gets applied once, because he is under the effect of a competing aura, but for enemies, they are hit by all three level 44 holy fire sources at once, essentially tripling the radial damage of the skill, and this effect is also used by Teslans with dual level 30 holy shocks and could theoretically be used for holy freeze and sanctuary by barbarians, but due to the lack of synergies for them, it would not be terribly effective, now this is why these are strong though, since most notably the paladin through natural synergies and the sorceress through her masteries can heavily boost, this tick damage by investing in the appropriate skills to basically give the full synergy boost and they both can combine it with conviction either naturally in the paladin's case or through infinity in the sorceress's case to strip away resistances to these effects.
This stacking effect is likely why see origins, only as low-level or end-game options rarely in between, since these tricks just don't work with the naturally cast auras and also why will likely never see actory mercenaries gain access to elemental masteries.