How Do I Read the Elemental Stats on an Enemy?

[Simoom]

for example.  Enemy stat shows Radiation Sign with 3 +'s next to it.  Pluses means it's strong against radiation or weak against radiation?

[Xardis]

It means it takes +25% times the number of + from that element. Same with -. On top of that, if it reffers to armour type, bonus damage also means the % of armour that daamge type will ignore. Corrosive has +++ vs Ferrite Armour so it does +75% damage and that damage is done as if the enemy had 1/4th of his armour. Same case with Radiation damage and Alloy Armour.

Edited October 31, 2018 by Xardis

[taiiat]

positive is extra Damage, negative is less Damage.

generally, this is 25% per +/-. there are some exceptions though.