When I started playing Dungeoneer back in 2014, I correctly assumed that you were meant to add your Movement attribute to Movement Threat checks. I made this assumption because you added your other 2 attributes (Melee and Magic) to checks related to them. This blog post exists exclusively to reinforce the correctness of that assumption.
I know this seems like a non-story, but I keep doubting myself on the rule. Every time I sit down to play a Dungeoneer campaign, which is about twice a year, I fool myself into thinking that the Movement bonus is too good. What other attributes do you get a full +2 at level 1? Well actually it does happen, but nevertheless I always have my doubts. Then I go and look at the rules, and I can't find anything confirming or refuting it, and so I just keep playing, sometimes adding it and sometimes not adding it.
Proof of ruling
I was playing Vault of the Fiends recently and I came across the Dimensional Shift card. It is a Trap card with a Movement Threat requiring 7+ on a d6.
It is not possible to roll a 7 on a 6-sided die. The only way to beat this Trap card is to roll a d6 and add a modifier, and as usual the modifier is indicated by standard iconography for Movement.
Solution
Let there be no further doubt. You do indeed add your Movement attribute to Movement Threats in Dungeoneer
Photos Creative Commons cc0, but all photos contain products and artwork copyright by Atlas Games and Thomas Denmark.