They can't be countered or redirected by standard instants and activated abilities, so the only way your opponent can interact with them is with something already in play
The first thing to note is that the colored border continues on the bottom of the cards, whereas newer cards only have this colored border on the top and sides
Bracket 1 (exhibition) and 2 (core) decks generally avoid game changers
Damage and Damage Counters Most attacks deal damage, and the amount of damage an attack does is listed to the right of the attack name
In these instances, the player will draw X cards and discard X cards, where X is equal to whatever term the ability states
Whenever your opponent casts their first non-creature spell each turn, you may draw a card, unless your opponent pays X (where X is Esper Sentinel's power)