“I leap from the ledge and try to land on the dragon’s back!” declares the barbarian. What follows? The answer is probably different at every table. Although improvisation is a staple in 5e to be celebrated, in these high-risk cases it’s often a boon for both the players and GM to know what kind of rolls might follow, what the monster might do in retaliation, and what sort of advantages they have to gain (beyond the sheer cinematic glory of it!)
This Colossal Creatures ruleset was forged inside my personal homebrew campaign, heavily inspired by Shadow of the Colossus, Monster Hunter, and my primal obsession with tiny heroes clashing with huge monsters. These rules aren’t finished, and I’ll likely go on tweaking them forever and ever, so I encourage you to keep what you like, change what you will, and drop the rest. Please leave your feedback in the comments too! Together we can help this ruleset evolve into something great.
Despite the wording so-far, these rules can be used for Large monsters, Colossal monster, or anytime a smaller creature wishes to grapple a larger creature. They are even useful for vehicles, moving terrain, and other uncertain footing!