There's been various changes over the years, juggling points for tries and penalties, introducing sin bins, and so on, but it isn't really anything fundamental.
Where you do see changes has been in the physique of players, and to some extent it's cyclical. Teams adapt to circumstances, player sizes and types change, and then some outlier will come along and with a visionary coach shake things up again.
Wings used to be lighter sprinters, then Jonah Lomu came along and proved that wings could be big (at 6' 5" he towered over most players, average height for the time was 6' 1") and still fast.
People just didn't have the strength or weight to stop him, especially out on the wings. Players of sufficient size would typically be one of the forwards, the bigger players that dominate a scrum.
Teams adapted to the new paradigm though, wingers started getting bigger and stronger as tactics changed, and we've seen size and weight fluctuate back and forth a bit, sometimes internationals favour lighter faster, sometimes slightly slower but stronger.
Ehh, I'm in a club with some old timer alumni, and the stories they tell (and 1970s rugby videos on Youtube I've seen) tell a different story.
Even 20 years ago at a club level, many things were allowed that aren't now: Quicker scrums, high tackles, raking the ruck with cleats, and general hooliganism seem to have been more par for the course than today.
I saw a match from 1977, and there was no Croutch/Bind/Set. The scrum just walked up toward each other and engaged immediately. More dangerous, but a lot different than today. The line-outs didn't lift; the hooker threw the ball in like a football lob.
The reason for advent of behemoths like Lomu was the allowing of wholesale substitutions.
This meant that players no longer had to play the full 80 minutes and so endurance could be sacrificed for power.
This in turn has likely contributed to the increase in serious injuries in the game, particularly concussions.
Rugby has changed a hell of a lot since the advent of professionalism in 1995 and they probably need to row some of those changes back imo.
There's been various changes over the years, juggling points for tries and penalties, introducing sin bins, and so on, but it isn't really anything fundamental.
Where you do see changes has been in the physique of players, and to some extent it's cyclical. Teams adapt to circumstances, player sizes and types change, and then some outlier will come along and with a visionary coach shake things up again.
Wings used to be lighter sprinters, then Jonah Lomu came along and proved that wings could be big (at 6' 5" he towered over most players, average height for the time was 6' 1") and still fast.
People just didn't have the strength or weight to stop him, especially out on the wings. Players of sufficient size would typically be one of the forwards, the bigger players that dominate a scrum.
Teams adapted to the new paradigm though, wingers started getting bigger and stronger as tactics changed, and we've seen size and weight fluctuate back and forth a bit, sometimes internationals favour lighter faster, sometimes slightly slower but stronger.