Does skipping your combat phase prevent triggered abilities that say 'at the beginning of combat'?

"At the beginning of combat" triggered abilities use the beginning of the combat phase's first step — the beginning of combat step — as their trigger event. According to CR 615.1, when a phase or step is skipped, it is treated as though it simply does not occur that turn.

Because the beginning of combat step never happens when combat is skipped, the game never reaches the point where those triggers would be checked. Per CR 603.2, a triggered ability only triggers if the event described in its trigger condition actually occurs. No step means no trigger event, so nothing goes on the stack.

This is an important interaction with cards like Vorinclex, Monstrous Raider or effects that say "skip your combat phase" — any ability that would trigger at the beginning of combat on your turn is simply lost for that turn cycle.

Concrete example: You control a creature with an ability that reads "At the beginning of combat on your turn, this creature gains +2/+0 until end of turn." An opponent's effect causes you to skip your combat phase this turn. Your combat phase never occurs, the beginning of combat step never exists, the trigger condition is never met, and your creature does not get the +2/+0 bonus this turn.

Note: If an opponent's card gives them an extra combat phase on your turn, "at the beginning of combat" abilities can trigger during that phase instead, since those steps do occur (CR 615.1 only skips the specified phase, not any added ones).