What if the owner can't benefit from Shaku of the Three Mountains?

They get Prestige +0.05/month instead.

Personal artifact · Regalia

Shaku of the Three Mountains

IllustriousUniqueAll Under Heaven

Shaku of the Three Mountains is an illustrious regalia artifact in Crusader Kings III: Building Construction Cost -10%, Building Construction Cost -10%, Building Construction Cost -10%, Building Construction Time -10%, Learning +1, Stewardship +1. Quality 100 and wealth 100; maximum durability 150, and it does not wear out. It needs All Under Heaven. Patch 1.20.0.3, from game/events/decisions_events/ep4_decision_events.txt.

Quick answers (2)

What does Shaku of the Three Mountains do in CK3?: Building Construction Cost -10%, Building Construction Cost -10%, Building Construction Cost -10%, Building Construction Time -10%, Learning +1, Stewardship +1 (patch 1.20.0.3).
What if the owner can't benefit from Shaku of the Three Mountains?: They get Prestige +0.05/month instead.

A lacquered ceremonial baton carved from sacred island cedar, symbolizing the unification of clans under a single divine mandate.

Effects

For an owner who can't benefit from it

The template gives these instead of the effects above when its “can benefit” check fails:

Prestige+0.05/month

Who can benefit (can_benefit) (1 line of game script)

culture = culture:ryukyuan

As written in game/common/artifacts/templates (ryukyu_shaku_template).

How it is made

Made only inside events; no scripted effect to call from the console.

Also created in event major_decisions.6001.

Source: game/events/decisions_events/ep4_decision_events.txt, common/modifiers (ryukyu_empire_shaku_modifier), common/artifacts/templates (ryukyu_shaku_template) and the English localisation, Crusader Kings III 1.20.0.3.