Anybody that loved the previous two Season 4 episodes when the season returned to form, after a to me a slight quality slump between "American Dream" and this (the only "great" episode for me between this period being "Censure"), and their intricate plots would understandably expect a lot from "Wager". Speaking as one of those people, in terms of loving those two episodes and expecting a lot, despite on paper the story for "Wager" not sounding out of the ordinary.
"Wager" to me is a well done episode of Season 4 and of 'Law and Order' overall on the whole with quite a lot of excellent things, namely the performances. At the same time "Wager" hasn't ever struck me as a great episode and is a couple of steps down from "Big Bang" and "Mayhem", the previous two episodes, which had more complexity in the story and writing. As far as the Season 4 episodes go it's one of the weaker ones, that it is that yet still manages to be well done says a lot about the high quality of the season.
Plot-wise, "Wager" is fairly unexceptional. There's not an awful lot that's surprising or original here (for instance the perjury is quite obvious and pretty silly) with a seen it all before vibe at times.
Did think too that it could have done with a consistently tighter pace and more tension. Compared to other episodes of Season 4, this felt slightly on the bland side.
However, the production values are slick as always and the music is haunting and doesn't overbear. The script is taut and thought-provoking, especially in the second half. The detective/investigative part of the plot though is every bit as intriguing with Briscoe delivering amusingly on the wisecracks, if on the ordinary side, and the whole Tercel part is very entertainingly done.
Even if there is not much special about the story enough of it maintains interest, especially when things become less obvious later. There is a twist that is well executed. The acting is very good, with sinister Ray Aranha stealing every second he's on screen.
In conclusion, well done. 7/10