This is a simple, very simple mind you, script to make some pretty interesting dungeon additions via the use of placeable barrels that when hit explode.
Unlike most scripts this isn't an On Death event but rather an On Physical Attack so be careful how you hit it.
The effect is a simple instant spell string that casts a level one fireball on the Barrel itself, this is not user friendly and will hurt anyone within the blast radius.
This is fairly simple to improve upon and I've designed the script and the placeable barrel to be easily customizable. The barrel can be found under the Custom Five tab of your Toolset, and the script is named ns_exp_bw you can easily modify them both to have varying strengths by simply altering the spell level of the fireball cast and changing the script name to, for example, ns_exp_bs(S for strong as opposed to W for weak.)
To install simply open your toolset go to the file tab, with a module open and loaded of course, select import and choose the .erf titled ns_exp_barrel1, that will add the script to your module and place the example Barrel in your custom placeable tab under the sub category of Custom Five.