If it's in your bag or equipped, it's easy: just count the dots. But if you're looking at the Auction House, or rewards from a mission, or a merit vendor, all I can see is the "hold ctrl+click" message, which tells me it has slots, but not how many.
_________________________________________________ @flamingbunnyman in game. Formerly @Roderick in City of Heroes.
I believe if it's below 30, any moddable gear will only have one slot -- taking offense, defense or utility mods depending on gear type.
At 30+, if the gear is blue it will have 2 slots -- one for stat mod (armor for defense or utility gear, enhancement for offense gear) and one for off/def/util. So you could put a Gambler's gem for crit strike and an Ego Enhancement mod in a blue lvl 35 gauntlet.
I have a level 40 green helm with 2 slots, so it's possible that lvl 40 gear has two slots whether it is green or blue, not sure about that.
lvl 40 purple heroic has 3 slots and purple legion has 4 slots. Not sure if lower lvl heroic/legion has less slots, and if it does what the cut offs are.
But to answer your question dirctly, there is no way to tell, just have to learn what gear has what slots basically.
Note that level 31+ Green Primary Utility will have 2 slots as if it was Blue (Blue Primary Utility does not drop, any you have will be mission rewards).
Comments
At 30+, if the gear is blue it will have 2 slots -- one for stat mod (armor for defense or utility gear, enhancement for offense gear) and one for off/def/util. So you could put a Gambler's gem for crit strike and an Ego Enhancement mod in a blue lvl 35 gauntlet.
I have a level 40 green helm with 2 slots, so it's possible that lvl 40 gear has two slots whether it is green or blue, not sure about that.
But to answer your question dirctly, there is no way to tell, just have to learn what gear has what slots basically.
1- and 2-slot primary gear will drop from MoBs, but Heroic has to be earned with Silver Champion Recognition and Legion is lockbox-only.
Heroic and Legion will always be purple.