Are Junglers Required?

[Tojara]

I'd say yes.

Usually you want two heroes to be solo and using a 2/1/2 split gives you a pretty massive disadvantage. That second hero that is forced to lane with another that benefits a lot from solo is going to be completely gimp you.

Jungle gives two heroes solo and opens up ganks/map control. Which is incredibly important.

[Bombkirby]

I did get my answer guys. ^_^' This is pretty old.

[Icpie]

Higher rated games, no jungler means they either stacked trap/teleporting chars, or tanky diving chars like lee sin, galio or malph etc. Jungle is still being cleared at a steady rate and being warded etc though.

[Nyon]

You are at a great disadvantage if you do not play with a jungler.