Sorry for late reply, only just noticed you posted again.
Larger chains are events that take place in sequence. Letting your mood get too low and triggering the Viktor chain for example. Each time you visit him, a new sequence in the chain is played.
Other areas that have event chains are if you search the dark and damp room at night.
Can also find events in the storage room climbing u the shelf or opening the vent. There are some when you try and pry the pipes in the utilities room. Sleep events and general walking around events.
If you are using cheats, raising your stats will make you avoid some events and cut short others. So don't be so eager to bump your stats up too high.