Non-Serious 3NT/3S
When we find a Major suit fit at the 3-level in a game forcing auction, then partner is usually expressing interest in slam (because without slam interest, partner would have applied the Principle of Fast Arrival and bid 4M.) In this case, now we usually express whether we have slam interest or not by either making a cuebid or simply bidding game with 4M. A partnership can use a gadget called “Non-Serious 3NT” to gain even further clarification about a player’s level of slam interest.