Flying Buffalo has released a PDF of the 4th edition of the Tunnels & Trolls rules, and it is available HERE. I highly recommend the purchase, to show that there is interest in the old crusty versions. T&T 4th has a great deal of charm, and the power curve is notably lower than that of the popular 5th edition. I think it's a great framework if you want to keep your game really simple, or to have a nice skeleton upon which to build your own wacky creation. At any rate, the $4 price is tough to beat.