Let me start with the corruption system since it's a pretty important mechanic once you reach act iii. You'll find vaal orbs dropping around that time and they're your first taste of item corruption. Using them is straightforward, just right click the orb and left click your target item but remember, there's no going back after that.

For something a bit more interesting, check out the corruption altars in places like vaal ruins and jiquani's sanctum. These work differently - you'll see a triangle interface that you drag onto items for corruption effects. The results can be pretty wild, from adding powerful modifiers to completely changing socket counts, or sometimes just marking things as corrupted with no other changes.

If you're new to corrupting, start with skill gems since they're easier to replace and can actually get some nice benefits like extra sockets. The smart move is to avoid using corruption on any gear you absolutely need until you're comfortable with the system, since corrupted items can't be changed anymore. More experienced players might want to try their luck with tier 15 waystones, as corruption can bump them up to tier 16, but that's definitely riskier territory.

For the really ambitious stuff, look into omens of corruption later on - they remove the "no change" outcome and make things more interesting, especially when you're working with those double-corruption altars in special areas like the temple of atzoatl.