Can my friend, who is a swordmage, and I, who am a battlemind, both have the same enemy marked at the same time?
I tried to read the rules and look up the answer but I am pretty new to D&D.
No, a creature can only be marked by one opponent at a time.
From the Rules Compendium, p232 (emphasis mine):
- The creature takes a -2 penalty to attack rolls for any attack that doesn't include the marking creature as a target.
- A creature can be subjected to only one mark at a time, and a new mark supersedes an old one.
- A mark ends immediately when its creator dies or falls unconscious.
A creature can only be marked by one person at a time. When a 2nd person marks the creature, the 1st person's mark is removed.