D&D 4e Rules: Blast and Burst

When my group first decided to try D&D 4th Edition, we had no prior experience with pen-and-paper RPGs and our main concern was being confused and overwhelmed by the rules. While our first sessions were certainly a little rough around the edges, we quickly picked up the basic concepts and had a lot of fun. Months later, our knowledge of the rules has gradually increased, but not a session goes by without us reading a rule we'd previously missed or misinterpreted.

The differences between blasts and bursts were something that we struggled to wrap our heads around at first, so I made a few images and descriptions for us to use as quick references. Hopefully others might benefit from them too.

A blast is what you might imagine when a dragon breathes fire. It must originate from a square within the users space and the blast area must occupy at least one adjacent square to its origin. The area that the blast fills is always a square, the width of which is specified by each power. For example, a blast 2 fills a 2-square-by-2-square area. A blast only affects targets in its area if there is line of effect from the origin square to the target. Blasts do not provoke opportunity attacks.

Blast 2 by a medium sized user.

Blast 3 by a large sized user.

There are two types of burst attack; close burst is what you might imagine if an enemy swung a flail 360 degrees, area burst is what you might imagine if an enemy threw a barrel of oil that exploded as it smashed on the floor.

Close bursts extend outwards in every direction from the user. The distance that the close burst extends is specified by each power. For example, a close burst 2 extends 2 squares in every direction from the user. The actual size of the area varies depending on the size category of the user. For a medium sized user that occupies a single square, a close burst 2 would actually fill a 5-square-by-5-square area with the medium user in the center square. A large sized user occupies a 2-square-by-2-square area, so a close burst 2 would actually fill a 6-square-by-6-square area with the large user in the center squares. A close burst only affects targets within its area if there is line of effect from the user to the target. Close bursts do not provoke opportunity attacks and the user is not affected by their own close burst, unless the power states otherwise.

Close burst 2 by a medium sized user.

Close burst 1 by a large sized user.

Area bursts can originate from a square up to a range from the user. The burst then extends outwards from the target square in every direction. The range and burst distance are specified by each power. For example, a burst 2 within 10 squares means that the burst can be placed up to 10 squares away from the user and the burst would then affect its origin square and every square within 2 squares of it. An area burst can provoke opportunity attacks and unless the power states otherwise, an area burst can affect the user.

Area burst 1, within 5 squares. Note that the origin square is also affected.

Area burst 2, within 5 squares. Note that the burst can be placed anywhere up to 5 squares, it doesn't need to be maximum range. The user can also be affected by the burst.

So if anyone wants to try D&D 4th Edition but is worried about learning the rules, don't be! You won't be alone in not knowing or misunderstanding some rules and you certainly don't need to know every rule from the very beginning (or even use them all, when you do know them). Start playing and having fun, your knowledge of the game will develop naturally.