From rpg.net

"We had a nice old school moment in last night's 4e session. The party had advanced into the enemy king's bolthole cum treasure chamber, and killed the king; now they were going to get them some loot. One of the traps was a room full of mould that grew incredibly fast if fed on magical energy and emitted hallucinogenic spores. The party retreated, and one of them sprayed the mould with lamp oil before igniting it with a burning rag thrown from a sling.

Leading to thick clouds of hallucinogenic poisonous smoke.

The party's response? "Ah, sod this, it's too dangerous. We'll come back when it's burned itself out." And they noted the place's location and moved on.

Old-school to me says 'problem solving not via skill checks and rules but via OOC ingenuity and use of resources'. It also says 'bastard DM piles complication upon deadly complication onto simple looking traps'. And finally, it says 'the dungeon is cautiously explored as opposed to brainlessly moving through from encounter to encounter while pinging Spot checks.'"