We’ve house-ruled a few things in the heat of the moment and have adopted a few house rules as permanent fixtures for our campaign.
One of our permanent house rules is that if a melee or ranged attack is a natural 20, the PC can choose to either add ultimate to the damage roll or get an easy attack roll on another enemy. The other enemy must be within “close” range of the PC for a melee attack or within “near” range of the first enemy target for a ranged attack.
A second house rule we’ve adopted relates to magic. All of the magic in our campaign is in the form of mystical energy that’s directly channeled/summoned by the mage from an otherworldly realm through an imbued physical object (we call it a medium) and is thus WIS based. We use 11 distinct magical disciplines that are free-form in nature and PCs describe what effect they’re attempting to achieve and then roll.
Applying an area of effect (beyond close) or extending an effect for multiple rounds usually makes the magic attempt hard. Mages can choose to sacrifice 3 hit points (before rolling) to make a hard magic attempt normal or to make a normal magic attempt easy. They can also choose to sacrifice hit points (after rolling) to add an extra die of magic effort to either damage or duration or another effect at a cost of 3 hit points per added die.
A natural “1” has a 50/50 chance of turning the spell effect back on the mage, though they’re sometimes (based on the situation) allowed a check (stat selected based on its appropriateness) to take only half the effect.
A critical fumble (a followup “1” to the natural “1”) means that their magical medium object has been damaged. A damaged magical medium must have 1 heart of basic effort applied to it (following a sucessful INT roll by the mage whose medium it is) for it to be able to again channel magic. We’ve allowed a hero coin to be used to add d12 effort to a successful INT roll for repair.
We’re always evaluating and tweaking as we go!
That’s about all I can think of off the top of my head and sorry for the long-winded reply! ICRPG has been such a breath of fresh air for our table and has unchained the creativity of players and DM alike.
Excellent, excellent stuff.
Onward into dark and dangerous places!