I have been a DM for a while and I have a reocurring problem. I have a severe instigator who often does bad decisions. He poked a guy ,who had a power hammer, and got hit. Then he did it twice more before a PC dragged him away. He also insulted an elder blue dragon patron. He was level 2! He charged at a fortified and heavily manned wall suicidally, and was captured. How do you deal with this? I have killed his character for incredibly bad decisions a couple times, but that didn't work. I am a fairly lenient DM/GM. Can someone help with this?

The best thing to do may be to talk to him, one on one, outside of the game. Remind him that the point of a role playing game is to create that character and have the character act in a manner realistic to him or her.

Would a newbie adventurer ever insult or attack a blue dragon? Of course not.

Point out that it's fine to be a troublemaker - if that makes sense. Otherwise, these kind of actions just derail everyone's fun.

D&D is about more than rolling dice, but it usually takes a while for new and/or young players to really understand it. Open communication is your best bet.

If not? Kill him unmercifully. Have the gods smite his stupidity. In extreme cases, don't let him play.

Sometime, he makes great decisions. Other times, not so much. Sometimes, he says it when he doesn't mean to. He is getting better, but is sometimes still difficult to manage. It isn't extreme enough to kick him out. He is newm and somewhat young for D&D. In a couple years, he'll probably be better. He does sometimes play carefully, usually when someone else plays a stupid character.