Why Does The Amount of Damage my Weapon(s) does keep changing? Why Does the Amount of Defence my Armor Provides keep changing?

[Hickster]

I've been playing Terraria a lot recently, and i keep noticing this. For example, I have a Demonic Eye of Cthulu that does 162 damage (I just checked) instead of 115 damage. Also, my defence just went down to 81 and back to 86! (i didn't drink any defence potions or anything). This isn't neccesarily annoying, but i wanna know why this keeps happening. Here's what i have equipped:
-Beetle Helmet
-Beetle Shell
-Beetle Leggings
-Hard yoyo bag
-Guarding Mechanical Glove
-Warding Beetle Wings
-Warding Obsidian Rose
-Guarding White Horseshoe Balloon
(I try to get all my equipment to have a defence perk)
Does any of my equipment change my damage/defence output?

[Rhudda]

I don't know about defense, but damage has a range like in many games, and of course it depends on the target's defense, too.

[Lunacy]

that 5 defense could be from a statue of bast, which increases nearby defense by 5.

[zer00_993]

The glove increases melee damage by 12%!

That and there's a range for damage.

[Meow Cultist]

You need to think of the system like a real life thing. Hitting something on a different spot changes how much damage you do. In terraria they change damage values based on your CRIT chance.
Basically the more crit value a weapon has the more chance it has more damage with every single random hit.

You can higher this by getting the Goblin NPC getting a "lucky" modifier for instance.

Plz also note that some effects lower the defense of enemy's causing damage values to get higher.

Hope this helps

[Varanus]

If you have the dps beetle armor equipped, your damage increases as you hit enemies, up to 30%. You were likely looking at your weapon while the buff was still active.