I followed @Hey I Can Chan advice and put a prismatic burst (MIC 40) on my rapier. Now when I look into the spell description it says that the area of effect is a cone with a 60ft range, and that any creature within area will be targeted by a ray...
Which makes me think that I should pay attention at my placement, because it would be annoying to hit an ally. So I wondered how friendly fire is handled in D&D because so far I never saw it being applied whether in a campaign or a video game, and in case my understanding would be correct, and aside placing myself in a situation where no ally can possibly be in the cone, how are those situations handled?
Beside, my current character can easily change its placement by tumbling or using dimension leap, but I have a friend who is also planning to use the effect. I was wondering if there were items for either avoiding to hit allies or for allies to avoid being hit by a friend, and how to use flanking tactics without having a friend in the potential cone area..
Thanks for your advices.