Warhammer Info - Articles - Collision Detection
Warhammer Online will feature collision detection against enemies, but not against friendly targets.
What is Collision Detection?
Collision detection is the process where the game server tracks each player's location to make sure players aren't running through solid objects. Pretty much every game you've played employs some level of collision detection. Most MMOs, however, do not calculate collision detection between players (it can be a strain on the server's resources).
If you care to venture onto an MMO message board, "collision detection" strictly refers to the collision detection between two or more players. If collision detection is on, players can't run through one another. If collision detection is off, players can run through one another.
Collision Detection Against Enemies
Dark Age of Camelot (and many other games) melee combat saw the ridiculous antics of players constantly running through one another in order to perform side and back positional attacks. Collision detection, obviously, puts an end to that - and good riddance. Run-through combat was a stinky turd that had festered in the toilet bowl of MMO PvP for years.
The real benefit of collision detection, as far as I see it, is the new set of battle tactics available to players. Blocking choke points with tanks in Dark Age was more or less a laughable strategy as enemy melee characters could simply run through the tank and attack the caster classes. Now, blocking choke points in Warhammer may prove to actually be a useful tactic.
Collision detection also allows for some new strategy in open field combat as well. Characters that typically fall quickly (healers and casters) will no doubt still be the primary targets in PvP encounters. In Dark Age, the weak characters would respond by attempting to run away or find a groupmate that could Bodyguard them. In Warhammer Online, the weak characters can now use collision detection as a survival technique. Since collision detection between friendlies does not exist, a weak character can give his pursuers the slip by running through a friendly tank. The tank effectively clotheslines anyone chasing the weak character. If used correctly, collision detection can give a whole new meaning to playing a defensive tank and brings new opportunities for teamwork to the table.
No Collision Detection Between Friendlies
The major drawback of collision detection is the potential for abuse against allied players. Anyone that played Ultima Online back in the day probably remembers the asshattery that was jerks purposely blocking doorways and the like. Eliminating collision detection between friendlies obviously puts an end to this.
Friendly collision detection could also be annoying in massive battles. Imagine attending a Dark Age relic raid if collision detection between friendlies was enabled. It would take hours just to get everyone through the outer gates.
Earlier on, Mythic said that collision detection could be a temporary feature. Whether it was due to community support or a feeling in Mark Jacob's gut (he can't believe he ate the whole thing), it's now slated to be a permanent feature. And so far, it looks good.