For those new to trapper builds, there is an alternative/third way to play it

So we all know there's two mainstream strategies for triggering traps - Chain Reaction on Saboteur ascendancy and 0 Trap Duration from Sunblast + 2 Cheap Construction jewels for everyone else. However, there's always been a third one, which also comes with certain advantages - simply having enemies trigger all the traps as was intended.

This is actually possible to do if you get enough Trap Trigger Area of Effect. The reason is that Cluster Traps always throws its traps within 20 units of its targeted location. The base trigger radius for traps is 10 units and so if you scale that up enough they'll all trigger quite reliably from mobs (normal enemies are 2 units big, and bosses much more).

This also has the advantage of working with the various trap effects that actually require enemies to trigger the traps, such as Tinkerskin chestpiece, Blast Cascade passive and even those new Trapper gloves in 3.3.

You'll need over 200% Trap Trigger Area of Effect to do this reliably. Well, as it happens, that's more attainable now than ever before. You used to have to use multiple Hair Trigger jewels to do this, however, GGG just added Devastating Devices passive to the big trapper wheel to the left of Shadow, which has 40% of it (and there's another 20% on the High Explosives notable right next to it). In all, we now have 190% Trap Trigger Area of Effect on the Tree - 60% in the Devastating Devices cluster, 40% in the Master Sapper cluster near Acrobatics keystone, 70% in the Expeditious Munitions cluster and 20% in the Unstable Munitions cluster. Even if you leave out that last one, with 170% from the tree (plus an optional 40%-60% from one Hair Trigger jewel), you'll almost always have all your traps triggered by enemies (provided you throw them on top of the boss or in the middle of the pack).

This method saves you a belt slot as well as 2 (or 1) jewel slots AND allows you to play another class or ascendancy. Indeed, you might consider even skipping Chain Reaction on a Saboteur as well, in favor of the greater damage boost of Explosives Expert instead (since cooldown recovery isn't as important as it used to be).

Also, as a bit of bonus info - know that enemies triggering traps also gets higher priority than both Chain Reaction and 0 duration i.e. even if you do use either of those, if an enemy is close enough to trigger a trap, it always counts as the trigger event and hence activates all the 'traps triggered by enemies' buffs, so they're not incompatible together.

Anyway, just letting you guys there's another option from the two you usually keep hearing of. Cheers, exiles!

Edit: 1) It seems there was a Reddit post a few days ago where someone tested out this option to see how it played. You can read what his experience of it was like here - https://www.reddit.com/r/pathofexile/comments/8mph2w/information_hair_trigger_and_cluster_trap_test/

2) Also there's a video comparing the regular (no trap trigger AoE increases) trapper with the Sunblast and Chain Reaction options here - https://www.youtube.com/watch?v=HwIoMKgB0uA&feature=youtu.be As a bonus, he also talks about the relative power and importance (or lack thereof) of Shaper gloves for trappers.