OXO Variants

Here are some Noughts & Crosses variants . . . .

• 3x3 board with 3 counters each.  If all 6 counters are played without a winner, players may then move one of their counters to an empty space according to different flavours of the rules - (a) adjacent orthogonal only; (b) adjacent orthogonal or main diagonals; (c) adjacent orthogonal or any diagonal; (d) any!
  What are the differences in strategy and theoretical outcomes for these 4 varieties?
  For (a), Martin Gardner says that it is a forced win for the first player if they play their first move in the centre, but this is usually not allowed.  Then, he says, the game is a theoretical draw, but with lots of potential traps for both sides.  I can't remember playing this variant - I shall have to find an opponent!
  The internet is not definitive, but at least one of these was called 3 Men's Morris and played in England back in 1300!
   
• 3x3 Misère - whoever makes the first line loses.  Do the analysis yourself!
   
• 4x4 board, make a line of 4.  There is no central dominant square now, though going first is still a big advantage.
   
• Connect 4 - surely an OXO variant, with gravity as the extra twist?!
   
• Five in a Row (aka Gomoku).  The players, Black & White, take turns to place a piece of their colour on an empty space of a Chess board / Go board / Infinite board.  The first to make a line of 5 contiguous pieces of their colour wins.  A line of 4 contiguous pieces with a space at each end is a double threat and wins.  Going first is a considerable advantage, but do you think is it enough to ensure a forced win . . . ?  More details and lots of variations at Gomoku - Wikipedia.
   
• See the separate article (yet to be written) Gobblet (4x4) & Gobblers (3x3) for what I feel is the best OXO variation.

There are many more variants, with increasing levels of quirkiness, at Tic-tac-toe variants - Wikipedia.  However, I wonder if any of these are ever played?