The US has had the gameplay element since it's second season in 2001, and Canada since it's incarnation. Both continue to go out live and have a weekly eviction format with three episodes a week (usually Sunday, Wednesday and Thursdays, which are the live eviction). The Canadian version lasts for 10 weeks, the US version a little longer at 12-14 weeks. The live feeds have remained an important component throughout with up to four live feeds - although key gameplay elements are blocked from the feeds to save for the broadcast show, but within minutes of the feeds returning you can find out what has happened.
The Head of House is the winner of the weekly competition, usually live, who chooses the two nominees for the week and in addition gets their own suite for the week. The HoH though is not eligible to become HoH the following week, with the exception of at the final 3.
The week basically airs as follows:
Sunday:
- Competition. It used to be food related but now is usually related to a gameplay element, or the conclusion of the HoH competition
- Nominations - the HoH nominates two for eviction. In some seasons there is a third nominee, either chosen by viewers or through a competition element or twist. Various secret powers have generally been part of the twists in recent years for BBUSA.
Wednesday:
- Veto Competition and Ceremony - the HoH, nominees and three HGs chosen at random play in the competition. The winner can, if they choose to, save a nominee, with the HoH naming a replacement. They can also choose not too but often they'll be a "backdoor" strategy in play where the intended evictee is not nominated initially but as the replacement.
Thursday;
- LIVE Eviction - each HG votes live one by one in the diary room. HoH only votes in event of a tie. The nominees don't vote.
- LIVE HoH Competition - usually completed live but if an endurance comp will begin in the show then be resolved on the live feeds and in Sundays episode.
- Twists - usually any upcoming twists will be revealed to viewers, whilst if a public vote is required (such as for a third nominee or to give someone a power) it will usually open on eviction night.
At the final three stage a three part HoH comp takes place with the winners of part 1 & 2 progressing to part 3, where the winner decides who is evicted. The final two then face the jury - the last 7-9 evictees from the season - to determine the overall winner.
Brazil has a highly successful variation on the format which also includes a public vote - basically the HoH nominates one person, the other HMs nominate one person each to determine the second nominee and the viewers then vote to evict.