Far from Sherwood Forest
Area: A faily well-traveled road which winds deeper and depper into a forest is the setting.
Situation: Bandits have prepared an ambush and have prepared a net above the roadway within the trees. The net is obscured by branches and foliage, making it difficult to detect. A Perception check (moderate difficulty) is required to notice the net before walking into it.
If the party observes the net, they can stop before setting it off. Thus when the ambush is sprung, no surprise round is gained by the attackers (or the party gains intiative, depending on your RPG system).
If the party is on horseback and fail to see the trap, the net drops on the head and front quarters of the lead horse(s). The rider(s) must make a horsemanship proficiency check to stay mounted, otherwise he falls to the ground, taking fall damage.
If the PCs were not mounted, the net falls on them. It takes 3 rounds to untangle, during which time they lose Dexterity and shield bonuses and are -4 on all hit rolls. You can choose to give the party a dexterity or acrobatics saved to avoid being caught in the net as it falls.
After the net has either been noticed by the party, or fallen upon them, the bandits ambush the party. They appear on the road 60 feet ahead of the party, as well as in the trees and even on the road behind them. Unlike Robin and his merry men, these bandits waste no time attacking the party.
Enemies: Bandit Raiding Party (adjust according to party level)
(TSR Advanced DnD, Deck of Encounters, 1994)