I'm talking about Dungeons & Dragons: The Fantasy Adventure Board Game published in 2002 by Parker Brothers, a division of Hasbro.
In the "Actions" part of the rulebook it says:
Each Hero may take 2 Actions on each turn. You can choose to take 1 or no Actions if you wish.
The following Actions are all possible within the game and use 1 Action each:
It doesn't specify whether you can choose the same action twice in the same turn or not but in a later example (only in the Dungeon Master's Guide (pg. 8)) it says (explicitly for Monsters):
You can decide not to move or attack with a Monster or not to attack and take a double move. [...]
I am pretty sure, that they want to say that Monsters can't attack twice, but I am not so sure about player characters.