Can a warlocks contagion power spread to invisible enemies within range?
Here’s a quick inside look at game development: At times, while developers like to keep out specific language, editors often prefer to keep it in place. This was the case with our recent updates where we added specific language regarding targets that must be seen; this is not a wholesale change to all powers, just language applied where it was specifically felt to have been needed. When it comes to targeting enemies within line of sight, this requirement makes sense for some powers and abilities such as divine challenge—so that it isn’t used as a de facto see invisible (“I target the nearest enemy; now show me where he is!”), since by the rules you know if a power worked or not. For contagion, there seems to be more leeway. As the situation decries, your DM might well allow it to spread to invisible enemies. On that note, let’s conclude with a final thought that is known to all but well worth reiterating. When it comes to the rules and their application, nothing is wrong with DM Fiat.