If $\ch(k)\nmid\abs G$, every finite-dimensional $k[G]$-module splits into simple summands.Suggest a slogan
Let \(G\) be a finite group and \(k\) a field with \(\ch(k)\nmid \size G\). Then every finite-dimensional representation of \(G\) over \(k\) is a direct sum of irreducible representations.
If \(\ch(k)\nmid \abs{G}\), finite-dimensional \(k[G]\)-modules are direct sums of simple \(k[G]\)-modules.