From Guild Wars Wiki
This large rolling rock crushes anyone in its path.
- Concise description
A large rolling rock that crushes anyone in its path.
- This effect is used by rock boulders (which can be found rolling around in several dungeons), ice boulders, and lava boulders.
- Causes instant death, which does not count towards Survivor.
- When someone is enchanted with damage reduction enchantments 999 will come up as damage.
- Mechanically, they are invulnerable non-targetable NPCs that patrol along a specific path. Like all NPCs, they rotate when they turn, which can lead to some interesting visual effects of the boulder coming to a halt, turning slightly, and continuing on its path.
- After being killed by a boulder, this effect does not appear in the effects monitor.