Cross Pollination

Briefly: I am fine. Thank you to everyone who reached out to check in on me, concerned that my having not written a post in the last week portended something unpleasant. The truth is I simply wanted to take a break. Spring is here; the weather is warmer and now seemed a good time to start working on my garden, among other vernal chores. Regular posting will resume in due course.

In the meantime, here's another question to keep you occupied: have you ever imported a rule from one RPG into another? That is, have you ever come across a rule (or rules interpretation) in one game that you liked so much that you thought a different game would benefit from its adoption? In my own case, I found the way that Empire of the Petal Throne handles the rolling of hit points upon gaining a new level so clever that I've made use of it in every level-based RPG with increasing hit points that I referee. For those unaware, EPT says that, once a new level is gained, the player rolls all his character's hit dice and adds up the total. If the sum is less than his character's current hit points, he gains no new hit points; if the sum is greater, it becomes the character's new hit point total. I like the rule because it evens out a PC's hit points over time while still respecting the inherent randomness of using dice.

What are your favorite rules you've borrowed from another game?