Hold'em table

Three-handed, the button should open very wide, and 75o has enough straight potential to min-raise and pressure the blinds. Folding is too tight from the button at 100bb.

Holding AcKc in the small blind against a button min-raise, 3-betting to 800 builds value and takes the initiative out of position.

73o is far too weak to continue against a button open and a small-blind reraise to 800. Folding saves the remaining stack for better spots.

75 offsuit is far too weak to call a 4x three-bet out of position; with ~600 more to call into 1100 and poor domination risk, folding preserves chips for better spots.

Opening on the button with a playable suited one-gapper to apply pressure and play in position.

A3o is too weak to continue out of position against a button open; folding avoids dominated aces and reverse implied odds.

64 offsuit is far too weak to defend the big blind against a 2.5x raise out of position; calling risks poor equity realization for a marginal pot-odds edge.

J7o is dominated junk from the button and not worth a limp or open against two live opponents. Folding avoids putting chips in with a weak offsuit hand.

On the button in a 3-handed game, 97o is a marginal but playable open; raising applies pressure to win the blinds and gives me position if called.

Holding 72o out of position against a button open is an easy fold.

T7 offsuit is too weak to defend out of position against a button open to 3bb; folding avoids a dominated, low-equity spot.

King-Queen suited is a premier hand on the button in 3-handed play; raising 2.5bb for value and position.

Pocket threes have enough implied odds to call a 2.5bb button open and try to flop a set out of position.

Q6 offsuit is far too weak to defend the big blind against a raise plus a caller, and calling 150 more out of position with poor equity is -EV. Folding is clearly best.

Pocket threes are an underpair on a wet, three-diamond flop, so I check rather than build a pot out of position.

On a monotone and connected board where I hold no diamonds, checking behind with two overcards and a gutshot allows me to realize equity in position without risking a check-raise.

Pocket threes with no diamond are weak on a four-flush board, and a bet only gets called or raised by better hands. Checking is free and keeps the pot small.

We hold no diamond blockers on a four-flush board. Checking behind allows us to see a free river card rather than betting into an opponent who likely holds at least one diamond.

Pocket threes have no diamond and lose to any pair, straight, or flush on this four-diamond board. Checking is free and avoids turning a weak showdown hand into a bluff that better hands will call.

With King-high and no diamond on a four-flush board, our showdown value is essentially zero. Betting around two-thirds pot puts maximum pressure on any missed hands or weak pairs without a diamond.

Four diamonds are on the board and I have none, so my pair of threes loses to any flush and to most value bets. Calling 400 is not justified against this river bet.

K8s is playable on the button in three-handed, and opening to 2.5bb takes the initiative with position rather than flatting the blinds.

5-7 offsuit is far too weak to call a 2.5x button raise out of position; folding saves 200 chips with almost no equity edge.

J6o is too weak to defend out of position against a 2.5x open.