Bunkers
The R&A / USGA · 2023What you may remove and when touching sand is prohibited.
Before the stroke
A ball is in a bunker when it touches sand inside its edge, or lies in specified positions where sand normally belongs. A ball on grass inside the edge without touching sand is not in the bunker. You may remove loose impediments and movable obstructions. Do not test the sand, touch sand immediately ahead of or behind the ball with a club, or touch it during a practice swing or backswing, except where a rule permits.
Allowed contact and relief
You may dig your feet in for a stance, put equipment down, lean on a club for balance, and smooth sand to care for the course, provided you do not illegally improve conditions affecting the stroke. Breaching bunker restrictions brings the general penalty. Once the ball is outside the bunker, sand restrictions normally cease. Free relief from abnormal conditions usually stays in the bunker; unplayable-ball relief has separate options and penalties.
Sources & approach ↗