Ok my friend plays a {Thragtusk} but I thunderbolt it as soon as it comes in. Does the {Thragtusk} get any of his abilities?
Yes, it still counts as entering and leaving the battlefield. To get around this, you'll need setting like {Counterspell}. Simple killing it won't stop it from hitting the field.
RESOLVED
Yes because he actually enters the battlefield. You would have to play {Rewind} to keep him from entering the battle field which would keep his abilities from activating,
Good job guys, well answered.
To the original poster: if you would like more details on how enter-the-battlefield (ETB) triggers work, you want to learn about the stack. Check out "The Stack" thread stickied at the top! :)
Priority is very important here.
If your oppoent plays a creature and you let it resolve you cant do anything because it entered the field. You have to wait till your opponent puts something else on the stak or changes phases. In this case you can respond to thragtusk's gain life ability, but no sooner.
Yup. That goes for plainswalkers too. You can't do anything to it when it enters (like {Beast Within}) until you get priority! A lot of people seem to think pws can be killed right away for some reason. Never be afraid to correct them!! *gavel of justice*