I am just testing out the deck myself for the first time and am working through the rules. One card which confuses me is the Grim Junction card. It says "Traps +3 Threat".
+3 to what?
Traps played on a player in the Grim Junction have their threat increased by 3. Threat is clearly described in the 2.2 rules.
atlas-games.com/pdf_storage/ ... 2LoRes.pdf
Threats
Threats are used to represent a risk or difficulty a hero must overcome. Threats are not the same as combat, though they often take
place during a combat. A Threat is a special die roll where the opponent rolls 1 die and adds the score that the card asks for to the roll.
Usually this is his hero’s Melee, Magic, or Speed, depending on the form of Threat, but any score could be specified — even your
hero’s current Life points or Level. If the opponent matches or beats the Threat number, he receives the success result; otherwise he
gets the fail result. Unless otherwise stated, Trap-type Threats affect all heroes in the same space, but they each roll individually.
Example Threat
Player A spends 2 of Player B’s Peril to play a Trap on Player B. The Trap reads: “Speed Threat 5+, fail: take 1 wound.†Player
B rolls 1 die and gets a 3, he adds his Speed score of 2 to the roll. His total is 5, which equals the Threat of 5+. He overcomes the
Threat, but gets no reward because there is no explicit success result. If he had rolled 4 or less he would have suffered the fail result.
Thanks for the reply. It's so simple now you explain. Mind you, I had not encountered a trap card from the adventure deck when I posted the query. Ah, how it must be to walk with the confident swagger of an experienced Dungeoneer.
Glad to help. 
I hope my response wasn't taken as rude or condescending. I try to be concise when posting to the net to keep things short: my personal verbal style tends to be a bit wordy. I certainly did not intend any offense. If any was taken please accept my apology. 
EDITED TO ADD:
The maker of Dungeoneer (Thomas Denmark) does frequent this board and he also has a Dungeoneer forum on his own site that is very informative.
studiodenmark.com/forums/index.php
I was not offended at all. The "confident swagger" was, well, I suppose, roleplaying. The confidence one gets from being conversant with the rules, transfering to the game. Your hero character no longer steps with trepidation, but moves with the confidence experience brings.
Oh, and thanks for the Thomas Denmark site link.