Bomb traps lie hidden in the floor, detonating the moment someone draws too close. Generally, (as in Ultima V) the entire party is effected by such explosions, although in later years some members of the company might escape the brunt of the conflagration depending on where they were positioned.
Main Article: Energy Field
Energy fields are a group of magical barriers which cause a number of effects to those who make contact with them, including poisoning, magically induced sleep and various injuries. In earlier games, such as Ultima IV and V, such barriers would often block passages within a dungeon and would need to be Dispelled. In later games, however, trapped floors could cause these fields to activate without warning, causing harm to those who found themselves unexpectedly caught within them.
Only encountered in Ultima IV, this trap caused a torrent of heavy rocks to fall from the ceiling as intruders passed, bring considerable injury (a loss of 10-20 hit points) to all passing under it. As travelers had no way to disarm such snares, adventuring parties often had no choice but to endure these showers of rumble should they lie between the party and their intended goal.
Later in, Ultima V such pitfalls would effect the entire party, causing the group to fall to a lower level of the dungeon. Well prepared adventurers, however, could seek out and discover pits through careful examination of the floor, allowing them to descend without injury. A well-prepared group could even employ a grappling hook, that they might climb up to higher floors through such traps.
Similar to the devices which protect many a locked chest, poison traps launch small metal needles coated with venom into the bodies of unsuspecting travelers, leaving them to suffer the ill effects of a given toxin until they succumb to death or find a means of curing themselves. Such devices were featured in Ultima Underworld I and in both parts of Ultima VII.
By the time of Ultima VII projectile traps became increasingly common. Such devices would launch arrows or bolts of energy or fire at those who triggered them, causing injury and even death to those who were not able to quickly evade the hail of projectiles. Some even hurled missiles which would terminate in explosions, causing similar injuries as might be cause by bomb traps.
Spikes, Bear Traps and Caltrops
During Ultima VI, traps designed to maim or injure unlucky adventurers became a common feature in many dungeons. Such snares were often concealed until an unwary traveler stumbled upon them, at which point the trap would spring, causing considerable damage as the metal spikes and jaws characteristic of such traps penetrated the victims lower body. Such traps would often reset after an individual ecaped them and could only be permanently removed by means of the Vanish spell.
Caltrops, unlike earlier foothold traps, were free standing devices employed in later ages that could be picked up and scattered wherever one desired. While caltrops (particularly those treated with invisibility dust) were common in dungeons during Ultima VII, the were not exclusive to them.
These magical winds, encountered in Ultima III and IV, caused no direct harm to adventurers encountering them - but rather extinguished all sources of light a party might have with them, dousing torch and bring an abrupt end to any active light spells. Should the company not be able to restore their means of illumination, they would face a blind advance into the dungeon, putting them at risk of getting lost or falling prey to additional traps.