ToME: the Tales of Maj'Eyal

What's the radius on it at max rank? Debating replacing Stone/Eldritch/whatever Spikes with it on my next Stone Warden to save points, while still hopefully keeping a decent AoE option for when I need it.

I'll often wipe an entire group of trash mobs with a single slam. I'll open with Spikes if I see spellcasters within range, but Slam is probably my most-used talent. It's radius 7 at 5 points (6.5 effective level).