That's https://battlebots.fandom.com/wiki/Double_Jeopardy. The design rules are https://battlebots.com/wp-content/uploads/2022/09/BattleBots... - there are some explicit rules around projectile weapons, but there's also a degree to which interesting robots are likely to be granted some leeway for the sake of spectacle, as long as the production team are convinced that safety won't be compromised.