dominant strategy [dom-uh-nunt-strat-uh-jee]
1. A strategy is dominant if, a majority of the time, regardless of other variables like what other players do, the strategy earns the player the biggest payoff or least hassle.
EX. When an opportunity presents itself to a gamer, that leads to the greatest advantage or easiest/quickest experience, they usually take it. Unfortunately, this can lead to uniformity and repetition when games often are designed or intended to be played in such a way that players will find their own special ways to complete the game's goals. This can ultimately lead to players becoming bored or missing out on good game content that is only accessible via using other methods to complete goals. That is why dominant strategy is such an important thing for any game designer to consider. Before we talk about the comic above, let me give a super simple example of dominant strategy's limiting issues.
You give a player a simple shooting game and you tell them that they have a gun and grenades. The gun is supposed to be the primary weapon but, when the player discovers the grenades deal the most damage and they have an unlimited amount of grenades, they proceed to play the entire game without firing a single shot and conquer it with ease rather than learning the nuances of the game's gunplay. The way to discourage this, in easiest design, is to limit the number of grenades available to the player without making them feel like your cheating them out of the overpowered weapon. For example, you can make the grenades unlock or reload if they perform certain tasks (risk and reward).
In this, you can see how having a dominant strategy might bring down a game.
As for the Pokemon comic above, they can't really give you too many options because, like in the comic, if you had to choose between getting a Pokedex from the Professor or taking all three starters, you would probably choose the latter despite the moral implications because having three starters would seem the best option. In actuality, it would make the game's curve far easier as you'd be able to overcome more gyms with ease. Other ways dominant strategy can hamper Pokemon is overpowered pokemon, broken strategies, overpowered types/tms, etc.
And that's just some random thoughts on dominant strategy or, basically, "taking the easy way out" or "playing smart". Luckily, some gamers can look past dominant strategy and instead challenge themselves by either creating artificial limitations or odd courses to success.