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<blockquote data-quote="Balesir" data-source="post: 6096842" data-attributes="member: 27160">This is an example of &quot;diff'rent strokes&quot;, I think, since this is almost precisely what I don't want, and the reason is simple. &quot;Common sense&quot; isn't. The idea that an instantaneous ball of flame can set things alight seems &quot;obvious&quot; to some people. But - and bear in mind that I have studied chemical plant explosions as part of my job in the past - it's not actually that common.To get something to ignite you need to get it up to ignition temperature; for vapours and gasses this is pretty easy if the ignition temperature is not too high (and liquids will generally have a vapour layer on top of them), but for solids the boundary layer heat exchange mitigates heavily against such large temperature increases in very short periods of time. Even with military munitions, the explosion itself seldom sets anything on fire; it's the red hot shards of shell casing and the burning embers of wadding that tend to do that. The question becomes &quot;does fireball spread glowing embers or red hot shards around?&quot; - to which I generally answer &quot;no&quot;.So, given the rampant uncertainty of such things when they are decided based upon what the people at the table believe to be &quot;common sense&quot;, I would much rather have clear and malleable rules for such stuff. The model of &quot;reality&quot; migh not be perfect, but at least everyone has the same one going in.</blockquote>

[QUOTE="Balesir, post: 6096842, member: 27160"] This is an example of "diff'rent strokes", I think, since this is almost precisely what I don't want, and the reason is simple. "Common sense" isn't. The idea that an instantaneous ball of flame can set things alight seems "obvious" to some people. But - and bear in mind that I have studied chemical plant explosions as part of my job in the past - [B][I]it's not actually that common[/I][/B]. To get something to ignite you need to get it up to ignition temperature; for vapours and gasses this is pretty easy if the ignition temperature is not too high (and liquids will generally have a vapour layer on top of them), but for solids the boundary layer heat exchange mitigates heavily against such large temperature increases in very short periods of time. Even with military munitions, the explosion itself seldom sets anything on fire; it's the red hot shards of shell casing and the burning embers of wadding that tend to do that. The question becomes "does fireball spread glowing embers or red hot shards around?" - to which [B][I]I[/I][/B] generally answer "no". So, given the rampant uncertainty of such things when they are decided based upon what the people at the table believe to be "common sense", I would much rather have clear and malleable rules for such stuff. The model of "reality" migh not be perfect, but at least everyone has the same one going in. [/QUOTE]

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