Trans-rights have become one of the most hotly-contested equality issues of our time.
On 9 October 2020, World Rugby published its 'Transgender Guideline' which determines that trans-women who transitioned post-puberty cannot currently play women's rugby because of the resultant player welfare risks this creates. Trans-men may play men's rugby having provided "confirmation of physical ability", but cannot play women's rugby after the process of sex reassignment has begun if this reassignment includes supplementation with testosterone.
Given the intensely physical nature of the sport and the potential for catastrophic injury, rugby is better placed than most sports to justify its decision and fend off discrimination claims. The question is how other sporting bodies will approach the issue as this is one issue that won't go away.