How do you rule climbing onto larger creatures?

[Easy_Lee]

As per the thread title, how do you rule it when a human tries to climb onto a hostile dragon, or a gnome onto a hostile ogre?

There are some optional rules in the DMG specifying using the creature like terrain and making opposed athletics checks, IIRC. But those rules are optional. I want to know how people actually rule this.

I'm considering building a gnomish barbarian with Tavern Brawler. Climbing on larger foes is pertinent to the build. As I'm terrible at predicting how most DMs will rule a given situation, I'd like to get an idea of majority opinion.

[Armored Walrus]

IMG I would probably use the optional rules if this came up. I haven't seen it come up yet, though.

[Bubzors]

Giants play a large part of the current campaign I play in. I have made it my monks passion to climb onto every large/huge creature he can. It's working fantastically so far.

And we just use the optional rules in the DMG. They make sense and it's fairly simple. Pretty straightforward.

[Lombra]

In our games we use the optional rule. It works very well.

[ZB2017]

I didn't realize that there were optional rules in the DMG. I had been making checks based on situation (different value if the giant is engaged in combat with someone else, flanking, etc.)

[xanderh]

Been both a player and DM when it came up, optional rules were used both times. They're easy and simple to use, since they mirror the PHB grappling rules so closely.

[Potato_Priest]

Whether we treat it as terrain or not depends heavily on the monster. On a mammoth or a dragon turtle we might allow it, but a more mobile and awkwardly shaped opponent like a giant or a T. Rex would be practically impossible to actually stand on.

We do, however, allow people to grab and hang onto larger creatures of pretty much any variety.

At our table, it works just like grappling in reverse: it uses the initiator's free hand, the initiator's speed drops to zero, the target's speed is halved(sometimes we ignore that bit, depends on scenario), the initiator gets moved around by the target, and the initiator can end it at any time, while the target has to make a check to shake off the initiator.

[Vogonjeltz]

As per the thread title, how do you rule it when a human tries to climb onto a hostile dragon, or a gnome onto a hostile ogre?

There are some optional rules in the DMG specifying using the creature like terrain and making opposed athletics checks, IIRC. But those rules are optional. I want to know how people actually rule this.

I'm considering building a gnomish barbarian with Tavern Brawler. Climbing on larger foes is pertinent to the build. As I'm terrible at predicting how most DMs will rule a given situation, I'd like to get an idea of majority opinion.

The optional rules; There's no point reinventing the wheel.