What to you guys think are the best weapons (items) for defeating dragons?

Probably the weapons created for killing dragons like the Dragon's Bane.

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In the foul darkness one figure will emerge to save the world from evil and despair.... Light flashes as his sword comes down, and thunder rolls through the sky when he points his sword up to heaven to signal his victory....People whisper his name as he walks by, evil tries to hide as they sense his presence nearby.... His name? Link......

There is a sword and shield in windspear hills, the sword does double-damage against dragons. Cloudkill can be used (judiouscly) to weaken them piror to attacking.Breach takes down their magic defenses. Carsomyr is probably one of the best non-specific weapons to use.



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Grinch

Yes, the Dragonslayer long sword is useful against them, but will not exceed the damage dished out by a powerful 2 handed swords (i.e. warblade)

A really good tactic for dragons is to cast magic resistance on them. This will lower their resistance to a maximum of 40%, and even lower if your cleric or druid is low level. YOu can then seriously hurt them with offensive spells while your fighters take the front line.