Neither one "wins" outright. A Local Rule modifies or adds to how a specific Rule of Golf applies for a course or competition, and once a committee adopts one, it carries the same force as a Rule of Golf for that round. Per the Committee Procedures published jointly by the USGA and The R&A (current at the time of writing), a Local Rule can change a Rule but is not meant to waive one outright, and only Local Rules consistent with the governing bodies' own guidelines are authorized; a round played under a Local Rule that isn't authorized is not considered to have been played by the Rules of Golf at all. So the honest answer to almost any "is this allowed here" question is: the base Rules of Golf say X, and your committee may have adopted a Local Rule that changes it for this course or competition. Check the card.
What a Local Rule actually is
A Local Rule is a modification of a Rule, or an additional provision, that a committee adopts for general play at a course or for a specific competition. It exists because a single global rulebook can't anticipate every course-specific hazard, layout quirk, or maintenance situation, such as an out-of-bounds line that runs unusually close to a green, an environmentally sensitive area that needs protection, or temporary conditions from course work. Local Rules are how a committee handles those without needing a new global rule.
Model Local Rules, the pre-approved menu
Rather than letting every committee draft its own Local Rules from scratch, the USGA and The R&A jointly publish Model Local Rules, a pre-approved set of roughly 90 optional provisions a committee can adopt as written, or adapt as a template. This is where the rangefinder question actually lives: whether distance-measuring devices are permitted for a round depends on whether the committee has adopted Model Local Rule G-5, covered in full at /are-golf-slope-rangefinders-legal/. It's also where things like preferred lies ("winter rules"), out-of-bounds definitions for specific holes, and drop zones for awkward hazards get formalized.
Common Local Rules a casual golfer actually runs into
A handful of Model Local Rules come up often enough at ordinary clubs that they're worth recognizing by name, even without memorizing the details. Preferred lies, sometimes called "winter rules," allow lifting, cleaning and placing a ball in the general area under specific course conditions, typically adopted when fairways are wet, thin or under maintenance. Distance-measuring device permission, the Model Local Rule G-5 already mentioned, is another common one. Environmentally sensitive areas get their own Local Rule defining them as no-play zones with mandatory relief. Temporary immovable obstructions, like maintenance equipment or construction fencing, get a Local Rule spelling out relief procedures specific to that obstruction. None of these are automatic. Each is a specific committee decision, adopted or not, and stated somewhere on the scorecard or Notice to Players if it's in effect.
What a Local Rule can change, and what it can't
A committee has real authority here, but it isn't unlimited. A Local Rule can modify how a Rule applies to fit local conditions or competition needs. What it isn't supposed to do is waive a Rule of Golf outright or contradict the guidelines the USGA and R&A publish for authorized Local Rules. If a course's own Local Rule isn't consistent with that guidance, it isn't a valid Local Rule under the Rules of Golf, and a round played under it technically isn't a round played by the Rules of Golf, a distinction that mostly matters for competitions that need to certify they were played under the actual rules, such as for handicap purposes.
Where to actually find a course's Local Rules
The scorecard and the Notice to Players (a document a committee issues for a specific competition, often posted in the pro shop or handed out at registration) are the real sources of truth for what's in effect on a given day. A general article, including this one, can explain how the Local Rule system works; it can't tell you what your specific club has adopted, because that's a decision made locally, course by course and sometimes competition by competition at the same course.
Casual rounds vs rounds played under the Rules of Golf
None of this has force in a fully casual round the group hasn't agreed to play under the Rules of Golf, the same distinction that runs through every other equipment and conduct rule on this site, covered generally at /golf-equipment-rules-for-amateurs/. Local Rules become relevant the moment a round is played competitively, or under a committee's authority, which is most club competitions and most handicap-posting rounds.
Why the same question can have two different correct answers at two different courses
This is the part that actually causes arguments. Two golfers from different clubs comparing notes on "are rangefinders allowed" or "is that a lateral hazard or a penalty area here" can both be correctly answering a question about their own course's Local Rules, while genuinely disagreeing, because each committee makes its own adoption decisions. Neither is wrong about the Rules of Golf itself; they're each accurately describing a different Local Rule environment. The base Rules of Golf are globally consistent (Rule 4.3a on distance-measuring devices means the same thing everywhere), but whether devices are permitted at all in a given round depends on a Local Rule decision that varies club to club.
The practical habit worth building
Before assuming a rule works a certain way at a course you don't play regularly, check the scorecard or ask the pro shop rather than carrying over an assumption from your home course or from something you read generally. This applies to distance-measuring devices, out-of-bounds and penalty-area markings, preferred-lie conditions, and drop-zone use, all common Local Rule territory. A five-second question at the pro shop resolves what a general article never can: what's actually adopted here, today.
FAQ
Can a Local Rule override the Rules of Golf completely?
Not outright. A Local Rule can modify how a Rule applies for a course or competition, but it's not meant to waive a Rule entirely, and it has to be consistent with the USGA/R&A's own guidelines for authorized Local Rules.
Are Model Local Rules automatically in effect at every course?
No. They're a pre-approved menu a committee can choose to adopt, in whole or adapted. Nothing on the list applies automatically without a specific committee decision to adopt it.
Where do I find out what Local Rules are in effect at a course I'm visiting?
The scorecard and the competition's Notice to Players, if there is one. Both are the actual local source of truth, not a general assumption carried over from another course.
Does a Local Rule apply to a casual round with friends?
Only to the extent the group agrees to play under the Rules of Golf and the club's adopted conditions. A fully casual round with no such agreement isn't governed by either the base rules or the Local Rules.
Why do two different golf clubs answer the same rules question differently?
Because each club's committee makes its own Local Rule adoption decisions. The underlying Rules of Golf are identical everywhere; what a specific committee has chosen to adopt as a Local Rule varies, which is why the same question can have two different, both-correct, answers at two different courses.
For the equipment rules that actually affect amateur golfers day to day, see /golf-equipment-rules-for-amateurs/. For the specific rangefinder Local Rule question, see /are-golf-slope-rangefinders-legal/. For where the official Rules of Golf text itself lives, see /rules-of-golf-official-source/.