Question about HSR/HCT Stacking.

I've recently decided to change my Air Wand to something more flashy, namely the Tormented Scepter which has an inherent HSR 20 to <attribute> and is inscribable.

Now since Wand Wrapping upgrades only give HSR <attribute> and HSR <ALL>, if HSR doesn't stack this would effectively mean the Wand Wrapping upgrade slot for the Tormented Scepter is useless.

So my questions:

1) Does HSR <attribute> stack with HSR <attribute> on the SAME WAND?
2) Does HSR <attribute> stack with HSR <ALL> on the SAME WAND?
3) Does the above apply to HCT as well?

Thanks.

EDIT: And by stacking I meant either through direct compounded chance or through separate "dice rolls".

-You can't have multiple HSR (or HCT) mods on the same item (one will correspond to the wrapping and the other will correspond to the inscription). You can, however, have a set of HCT and HSR mods on the wand and another set of HCT and HSR mods on the offhand.
-Percentages multiply. See here: http://wiki.guildwars.com/wiki/40/40

Apparently the Nightbringer has 2 HCT 20 mods, or is that just staff-specific?

http://wiki.guildwars.com/wiki/The_Nightbringer

So if the HSR mods don't stack, the Wand Wrapping slot for the Tormented Scepter is redundant?

You didn't quite understand my point. You can't have two HCT or HSR mods on a wand simply because the mods don't exist. To be more specific, you can't put a HCT mod in the wrapping slot simply because there is no HCT wand wrapping. There is a HCT inscription and a HSR wand wrapping, and the same system applies for offhands.

See here: http://wiki.guildwars.com/wiki/List_of_weapon_upgrades

Staves follow a different mod structure, so you have shown.

I think I did.

The question is whether the stat is considered an inherent property or is already "upgraded" per se.

For staffs and 2H magical weapons it looks as if these properties have a chance for being inherent while 1H wands and focii seem to come already upgraded.

Mods can close this topic now.

Oh, right. I misunderstood your issue. A wand (or offhand/shield) has either two inherent mods or has both an inscription and wand wrapping slot. When you trade an armbrace to the Deacon of Whispers the item you get already has a mod (a HCT wrapping for the wand). See here: http://wiki.guildwars.com/wiki/Deacon_of_Whispers.

Staves are mostly the same. Uninscribable staves have an inherent HCT mod, another inherent mod, and a prefix and suffix mod. Inscribable staves have an inherent HCT mod, an inscription slot, a prefix mod and a suffix mod.

//Leaving this open for further clarification if you need it