A number of choices:

Some might open 3♣ NV with the North hand as good suit, not defence and 2♣ being strong which would probably be passed out, though some Ss might raise to 3N with 3 clubs and and stops in the other suits.

Those playing a multilandy type defence can bid 2♣ over 1NT to show the majors. East responds 2♦ to show no preference and West bids the longer suit 2♥ s. North with a good 6 card ♣ suit should compete to the 3 level.

South has a choice between 1♠ and 1NT.

If South bids 1♠  West bids 2♥ s and North with a stop, 12 HCPs and a long suit will jump to 3N.

If West passes over 1N, North can bid either 2N, 3♦  or punt 3N with the long diamond suit. 3♦ is more descriptive but as it is unlikely to have a ♦ slam, better to try for a NTs game.

The question is what does West bid over the IN by East. He has 11 HCPs so many will either bid 2♠ (showing 11 HCPs) or 2N as an invitational raise.

Some may bid 3N straight away as they have a potential source of tricks in the 5 card ♣ suit.

Many West's who bid 2♠ or 2N will see East pass with a not very good 13HCPs.

Those getting to 3N often made as the best lead of a ♠ is not obvious. A good hand to try the "Play it again" function on the website to see how your play or defence could have improved.

A double of the 1♥ by South is normal.

West has 4♠ s a ♥ shortage so should bid 1♠, even though South is likely to have 4 and a minimum of 3.

North has either a 1N (15-16) or 2NT (17-18)  rebid that will be passed out. Some may have downgraded the poor 17 HCPs to 16 due to shape 4333 and  2 Jxx.

Standard 3♦ pre-empt by North.

Choice for South whether to bid 3N. A gamble unless you know your partner only bids relatively strong pre-empts.

Standard 1NT followed by a transfer to 2♠ .

A good result those who can make plus 1. This needs the J♣ s to be played from West.

The 2♦ by West over 1♠ will be 8+ HCPs so South can either go 3♣ which shows the shape and 16+ HCPs.

As it is duplicate scoring where 3N does well, some may jump straight to 3N over 2♦ s.

West can then show the support for ♠ s and East goes to 4♠ s. 

1♠ opening followed by a 2♥ overcall that is easily risen to 4♥ s.

Those playing weak jump overcalls will make it more difficult for N/S.

The double by South shows 8+HCPs and probably 4♥ s.

North would like to play in NTs so bids 3♠ s to ask for a stop.

South doesn't have it so shows ♣ support. 

North raises to 5♣ s. Bidding 4N as Roman keycard forces N/S to 6♣ s. Which makes.

Some souths may bid 4♥ s over the 3♠ bid to show 4 and controls thinking it may score better than 5♣ s. Which it does today.

1N by south and West can overcall 2♠ s. 

Generally do not allow opposition to play in 1N unless it is doubled. With wriggles they will probably find 2♥ s and you will still bid 2♠ s, so bid it now.

Over North finishing the transfer South can invite with 3♠ s or 3♣ s that shows shape and is invitational +.

North will probably pass the invite as values include a couple of Qs and no aces.

Some Souths may open with 1♠  and end up in 4♠ s. South's hand meets the rule of 19 for opening (length of 2 longest suits plus HCPs) nad has an offensive shape 5431. 

Lots of possibilities here.

1♣ opening though some may open 1N 5332 and 12-14. Followed by 2♣ stayman, 2♦ (no 4 card major) and 2♥ s have 5.

South will overcall 1♦  as double would ideally show 4 and a minimum of 3♥ s.

West is not strong enough to double, but could bid 1♥ .

North can show support for ♦ s.

East is too weak to bid again.

South sees no prospect for game so passes. 

West NV can risk a dodgy competitive second bid of ♥ s

This is likely to be passed around to South who will either go to 3♦ s or double to show 4♠  and reasonable overcall. North if brave enough to pass will collect a good score.

Depending on system West will open with a strong 2♣.

East not having an Ace and King will do a negative 2♦ 

West will show his suit.

East not having a first round control but good support for ♥ s with ♣ singleton should jump to 4♥ s.

The normal convention is that a raise to 3 shows a maximum 5-7, good support and a first round control. 

Depending on point count for 2NT East will try Stayman and not finding 4♠ s will end up in 3N.

Over 1♥  opener West may double - good shape, not a lot of HCPs but NV and only 3♠ s.

N/S can make 4♥ s and North should probably jump straight there. Otherwise East may show the 5♦ s and West will sacrifice in 5♦ s.

After North's 1♥ East will show 15-17HCPs and a stop by bidding 1N.

Many people will play an overcall similar to over an opening 1NT e.g. 2♣ s being stayman and red suit transfers.

So West will bid 2♥ s and East with a good fit for ♠ s and maximum may bid 3♠ s. Then West has a decision to pass or raise to 4♠ s with 3 HCPs. If in doubt and 6/4 go one more is often said. This time it works.

What to do with North Hand - 2N is a bit light, but you are a passed hand so South will not get carried away.

South shows his shape and values and North has to decide whether to bid 3 or 4♠ s. With values on his right the strength of Q♠ s and K♣ s has gone up so he can go for game.

North may be worried that 3♠ could be passed by South.

The alternative is to bid 2♣ as fourth suit forcing to see more what South has. However south may think this is because North only has 3♠ s, so may miss a slam, but may find the better duplicate score of 6N.

Some may open West hand with 3♣ s which after a double by North you end up in 3N from South.

After the 2NT opener from north south is thinking of a slam when he converts 3N to 4♠ s.

First transfer to ♠ s and then 4N RKCB and the response of 5♠ s shows 2 keycards (of 4Aces an K trumps) with the Q trumps.

So then bids 6♠ s

2♦  overcall should be raised to 3♦ by East.

Wests hand looks strong sitting with 1N on right and ♣ void. but partner passed so does not have great values. jsut pass will get a reasonable score.

North opens with higher ranked of 2 suits with 1♦ .

Then everyone bids theres suits and supports partner.

North wants to stop East / West getting in with Spades that may make a difficult decision.

North with 11 HCPs may bid 2♠ s that either shows 11HCPs or a weak minor. Depending on system South will show he is maximum by bidding 3NT or 3♣ (weak respose is 2NT) so will end up in 3NT that can go off on a spade lead. They have not bid stayman so partner might have a major and he has more points than you. So try to find his major and lead your shorter one that works here.

Difficult for non 5 card major players to find 4♠ s by E/W.

The only option is to bid 2♠ s by West with 3 cards.

3♥ pre-empt.

South cannot really double with no ♠ support and here partner will jump to 4♠ s. So pass.

With 3♥ s to add to 7 of partner raise to 4♥ s "law of total tricks."

Difficult for North to do anything now except pass.

Don't let opposition play in 1NT - overcall 2♦ s.

The 2N response shows 11-12 HCPs so an easy raise for West to 3NT.

The 2♥ bid shows a minimum of 8HCPs and 5+s so North can invite.

South with 10HCPs can accept the invitation.

Some East's may bid 2N rather than 3♦ as it often scores better in duplicate, but not this time.