Critical Miss

Natural 1s

If you roll a natural 1 on your first attack roll of a round, you must draw a card from the Critical Fumble deck.

Limitations

'Named' creatures cannot fumble more than once during a given encounter, and further 1s are simply misses.

PbP Games

The fumble will take the form of either a movement error (i.e. falling down, overshooting your mark), provoking an AoO from the target (i.e. your botch left you wide open), or something else that logically and reasonably fits the surrounding actions. Typically I'll allow a reflex save to avert wiping out with the DC based on your own level and the ability score that seems most relevant (i.e. Str when power-attacking, Dex when running, etc.).