This chapter is an alphabetical listing of the conventions the Ari–Tom system relies on, each with a short definition. Other chapters reference these by name, so the point here is to say plainly what each one means. A learner should be able to read an entry once and know what the convention does.
In any auction where one hand has bid three of a major and partner has not yet had a chance to raise, bidding ♣4 agrees that major and shows a stronger hand than simply bidding four of the major would. It is a way to set the suit and show extra values when the auction has used up the natural space to do so. This most often comes up in non-competitive auctions where the pair has eaten its own room, but it can also happen in competition when a natural cuebid is not available.
Fifth Suit Forcing is a checkback tool for non-competitive suit-suit-suit auctions where many pairs would play fourth-suit-forcing. It applies only when the fourth suit would be bid at the two-level; if the fourth suit is only available higher, this convention does not apply. In practice it works like a two-way (XYZ-style) checkback: the fourth suit is a puppet to the next-higher suit and shows invitational-or-weaker hands, while the fifth suit (the one above that) is artificial and game forcing. For example, after 1D-1S-2C, bidding 2D is the game-forcing fifth suit; to sign off in spades instead you bid 2H and pass the puppet. Notrump is always natural in these auctions. Opener is expected to accept the puppet with any reasonable hand, even holding shortness in the puppet suit; refusing the puppet shows both shortness and a bad hand.
Lebensohl is the pair's tool for slowing down after certain interference, letting them distinguish a weak, sign-off-style hand from an invitational-or-better one. A bid of 2NT acts as a puppet to 3C, which is the way to show the weaker hands; bidding a suit directly instead carries the stronger, forward-going meaning. It applies over an opponent's overcall in the relevant auctions and, per the July 16 review, over Opener's reverse (for example after 1D-1S-2H).
Smolen is used in response to a 1NT opening after Stayman fails to find a major fit. With game-forcing values and five cards in one major plus four in the other, responder jumps in the shorter major to show the longer one, letting the notrump opener become declarer. For example, after 1NT-2C-2D, a jump to 3H or 3S is Smolen and shows four cards in the suit bid and five in the other major, game forcing.
3♥ Smolen. Exactly 4 ♥, 5+ ♠, GF. 3♠ Smolen. Exactly 4 ♠, 5+ ♥, GF.
TaJ is the pair's main relay, used in both 1C auctions and in one-major-then-raise auctions. Responder shows hand shape in steps, and the relay tightens the picture suit by suit. The two-suited hands come first, then the one-suiters, then balanced hands. The 5332 shape step is never dropped, even when it might seem safe to do so, because keeping every step makes the relay clean and preserves flexible choices for responder.
The step structure, from cheapest, is: a 54xx two-suiter (relay for the second suit low/middle/high, then shape); a 55xx-or-better two-suiter; a 64xx hand; a six-card suit with shortness and no side four-card suit; the 5332 balanced hand; and finally 6322 or 7222. In auctions where responder is unlimited, the first step instead shows extra values and the next step repeats the relay.
TaJ carries its own keycard ask built in, so it does not lean on any separate keycard convention. Once the descriptive relays have finished, the next step (when it is 3S or lower) becomes an optional keycard sequence: the first step shows a bad hand in context, and the following step is the keycard ask. There is also a double-keycard mechanism to ask for the second suit's queen.
The pair plays South African Texas as a transfer into game in a major, unchanged and in good standing. It lets responder describe a long major with game values by transferring, so the notrump-type or strong hand ends up declaring.
XYZ is two-way checkback after a 1x-1y-1z sequence, and given the current agreements it applies only when the opening bid was 1D. Over Opener's 1z rebid, 2C is a puppet to 2D used for sign-off or invitational hands, while 2D is a game-forcing checkback with natural continuations.
Over that 1z rebid: 2C is the puppet to 2D (sign-off or invitational hands); 2D is the game-forcing checkback with natural responses; 2NT is a puppet to 3C for a club sign-off; three of a major is natural and invitational on a good suit; and jumping to three of a new suit is natural, 5-5, and game forcing.
After 2C, Opener is expected to complete the puppet to 2D with any reasonable hand, even with short diamonds; breaking the relay shows both short diamonds and a bad hand. Responder then clarifies:
Once Opener completes the puppet to 2D, Responder clarifies: pass to play in diamonds; three of a major is natural and invitational on an average-or-poor suit with sound values; 3NT is a balanced 5332-type choice of games; and two of a major (or 2NT) is an invitational hand, typically exactly five cards.