Attack is an arcade game mechanic. The DS Game has an equivalent mechanic in Attack Power, but it is replaced by Power in the TCG, which works differently in several ways.
Arcade
Eocarcharia arcade card, 550/650/550 Attack for R-S-P clearly visible, Scissors critical
A dinosaur has three Attack stats, one for each Sign. Two of them are usually the same, and the third is the highest, corresponding to that dinosaur's Critical Move, which is the Sign displayed on the card. Sometimes the three numbers are close together, while other times the critical move is far stronger than the others, allowing for variation among dinosaurs in an Element with the same Strength and Technique. Upon winning a Rock-Paper-Scissors move button match-up with the opponent, a dinosaur will inflict the Attack of the Sign they won with as damage to deplete the opponent's health bar.
Only certain releases of the arcade cards show the three Attack stats, which can lead people less familiar with Dinosaur King to incorrectly assume that the dinosaur's Strength stat relates to their attack (it's actually their health).
DS Game
It is called Attack Power in the DS game. Most mechanics are preserved from the arcade's version of Attack, the only major difference being that these stats increase as the dinosaur levels up throughout the game. In addition to their three Attacks, the DS game lists a number roughly equal to their combined total for quick relative power reference, but this total appears to be unused for any calculations. Dinosaurs feature one of several standard Attack Power stat curves, matching precisely at every level, which is determined by their Rarity star count, with more stars indicating a higher Attack Power curve; each regular Attack curve is paired with a particular Critical Attack curve in all cases. Attack Power curves typically start around 60-70 (non-Critical) or 75-85 (Critical) and raise by 9-12 (non-Critical) or 11-15 (Critical) per level. Attack Power, Rarity, and HP all scale together, while scaling opposite of Technique, which is highest when the rest are lowest and vice versa. Dinosaurs will have a higher Attack Power curve (regular and Critical) than others of the same Rarity if they are Attack Type; these do not match the curves of higher Rarities. Dinosaurs of all Rarities that are not Attack Type have the same Attack Power at levels 1 and 2, but differ above that.
Move Cards apply scaling factors onto a Dinosaur's Attack (such as x1.2) to increase damage instead of carrying base Power increases like in the TCG.
Trivia
Allosaurus arcade card, no Attack stats visible
- The only arcade waves whose cards show the Attack stats on the front are the Kakushin 1st, 2nd, 3rd, 4th, and 5th Editions, and the 6th Edition only on the back side not displayed on official website images, meaning only photos of actual Kaku 6th card backs would show it. For reference, the Kakushin Editions are the final of four groupings of releases, and only have Japanese versions.
- Because of this, only dinosaurs with a card released at some point during this group of waves can possibly have their Attack stats directly known and confirmed, leading to many dinosaur pages listing it as "(unknown)". Additionally, small print on the available card images from the official website can lead to some of the numbers being partially unreadable.