projectile problems and ai.

im atempting for the first time to make a full game in blender. and i got some basic workings down but i cantt get the bullet/projectile being shot by the enemy and the player to stop going through walls.
this is how i got the bullet being shot in the firstplace
iv got an empty parented to the gun and the projectil in layer 2 with some logic telling it to always go foward and in layer one theres a keyboard sensor for space that tells the empty to add the bullet object.
i tried making the bullet dynamic(wich stoped it from going throught walls) and giving some force or somthing but i couldnt quite get it to stop from dropping.
and anyone know how to get some ai i place?

Static to static collisions are not registered by the blender game engine. At least one object has to be dynamic in order for a collision to register.

Try lowering the mass of the bullet object. I think that should decrease the fall speed to appropriate levels.

For simple “AI” examples, you should check the ones I did for another user, in this thread:

well is there a way using logic?
im new to logic so im not sure if this is right
can i h ave a touch or colision sensor that trigers the projectile to be end once it hits the walls of my acting level?

Use the EditObject-EndObject actuator to end the bullet.

Learn all this and more from:

grrr thats what i did but it wouldnt work -_-

Make your bullet actor dynamic, add an always, and, motion (force +z, 9.8). Make it a ghost object, and now it will register collisions.